Number of the day: 66964

Paul Cohen was born on this day 84 years ago.

Properties of the number 66964:

66964 = 2² × 16741 is the 60290^th composite number and is not squarefree.
66964 has 2 distinct prime factors, 6 divisors, 13 antidivisors and 33480 totatives.
66964 has an emirp digit sum 31 in base 10.
Reversing the decimal digits of 66964 results in a sphenic number.
66964 = 16742² - 16740² is the difference of 2 nonnegative squares in 1 way.
66964 is the sum of 2 positive triangular numbers.
66964 is the difference of 2 positive pentagonal numbers in 1 way.
66964 = 20² + 258² is the sum of 2 positive squares in 1 way.
66964 = 30² + 92² + 240² is the sum of 3 positive squares.
66964² = 10320² + 66164² is the sum of 2 positive squares in 1 way.
66964² is the sum of 3 positive squares.
66964 is a proper divisor of 1381³¹ - 1.
66964 is palindromic in (at least) base -39.
66964 in base 39 = 1511 and consists of only the digits '1' and '5'.

The number 66964 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A066487: a(n) = min( x : x^4 + n^4 = 0 mod (x+n-1) ).
A270906: Number of active (ON,black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 214", based on the 5-celled von Neumann neighborhood.