Number of the day: 7928

Properties of the number 7928:

7928 = 2³ × 991 is the 6926^th composite number and is not squarefree.
7928 has 2 distinct prime factors, 8 divisors, 17 antidivisors and 3960 totatives.
7928 has an emirpimes digit sum 26 in base 10.
Reversing the decimal digits of 7928 results in a prime.
7928 = 1983² - 1981² = 993² - 989² is the difference of 2 nonnegative squares in 2 ways.
7928 is the difference of 2 positive pentagonal pyramidal numbers in 1 way.
7928 = 20² + 38² + 78² is the sum of 3 positive squares.
7928² is the sum of 3 positive squares.
7928 is a proper divisor of 113³ - 1.
7928 is palindromic in (at least) the following bases: 30, 34, and -33.
7928 in base 22 = g88 and consists of only the digits '8' and 'g'.
7928 in base 30 = 8o8 and consists of only the digits '8' and 'o'.
7928 in base 34 = 6t6 and consists of only the digits '6' and 't'.
7928 in base 44 = 448 and consists of only the digits '4' and '8'.

The number 7928 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A072895: Least k for the Theodorus spiral to complete n revolutions.
A107924: Even numbers n such that n^2 is an arithmetic number.
A172213: Number of ways to place 4 nonattacking knights on a 4 X n board.
A199118: Number of partitions of n into terms of (1,3)-Ulam sequence, cf. A002859.
A209990: Number of 2 X 2 matrices having all elements in {-n,...n} and determinant 5.
A258449: Numbers n such that A062234(n) = A062234(n+1) = A062234(n+2).
A318243: Triangle read by rows giving the sum of the number of k-matchings of the graphs obtained by deleting one edge and its two vertices from the ladder graph L_n = P_2 X P_n in all possible ways.
A320647: Triangle read by rows: T(n,k) is the number of chiral pairs of cycles of length n (1) with a color pattern of exactly k colors or equivalently (2) partitioned into k nonempty subsets.
A324802: T(n,k) is the number of non-equivalent distinguishing partitions of the cycle on n vertices with exactly k parts. Regular triangle read by rows, n >= 1, 1 <= k <= n.
A325193: Number of integer partitions whose sum plus co-rank is n, where co-rank is maximum of length and largest part.