Number of the day: 351

Properties of the number 351:

351 = 3³ × 13 is the 280^th composite number and is not squarefree.
351 has 2 distinct prime factors, 8 divisors, 9 antidivisors and 216 totatives.
351 has a semiprime digit sum 9 in base 10.
351 has an emirpimes digit product 15 in base 10.
351 has a triangular digit product 15 in base 10.
Reversing the decimal digits of 351 results in a triangular number.
351 = 7³ + 2³ is the sum of 2 positive cubes in 1 way.
351 = 176² - 175² = 60² - 57² = 24² - 15² = 20² - 7² is the difference of 2 nonnegative squares in 4 ways.
351 = (26 × 27)/2 is a triangular number.
351 is not the sum of 3 positive squares.
351² = 135² + 324² is the sum of 2 positive squares in 1 way.
351² is the sum of 3 positive squares.
351 is a proper divisor of 53² - 1.
351 = '35' + '1' is the concatenation of 2 pentagonal numbers.
351 is palindromic in (at least) the following bases: 14, 26, 38, -7, -12, -25, -35, -50, and -70.
351 in base 3 = 111000 and consists of only the digits '0' and '1'.
351 in base 4 = 11133 and consists of only the digits '1' and '3'.
351 in base 7 = 1011 and consists of only the digits '0' and '1'.
351 in base 14 = 1b1 and consists of only the digits '1' and 'b'.
351 in base 18 = 119 and consists of only the digits '1' and '9'.

The number 351 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A000217: Triangular numbers: a(n) = binomial(n+1,2) = n(n+1)/2 = 0 + 1 + 2 + ... + n.
A000931: Padovan sequence (or Padovan numbers): a(n) = a(n-2) + a(n-3) with a(0)=1, a(1)=a(2)=0.
A003325: Numbers that are the sum of 2 positive cubes.
A005251: a(0) = 0, a(1) = a(2) = a(3) = 1; thereafter, a(n) = a(n-1) + a(n-2) + a(n-4).
A005836: Numbers n whose base 3 representation contains no 2.
A014105: Second hexagonal numbers: a(n) = n*(2n+1).
A014580: Binary irreducible polynomials (primes in the ring GF(2)[X]), evaluated at X=2.
A014613: Numbers that are products of 4 primes (these numbers are sometimes called "4-almost primes", a generalization of semiprimes).
A074377: Generalized 10-gonal numbers: n*(4*n-3), n=0, +- 1, +- 2, +- 3,...
A084438: Positive integers n such that n!!!-1 = A007661(n)-1 is prime.