56981520 has 120 divisors (see below), whose sum is σ = 198034200. Its totient is φ = 14665728.

The previous prime is 56981479. The next prime is 56981527. The reversal of 56981520 is 2518965.

It is a happy number.

56981520 is a `hidden beast` number, since 56 + 9 + 81 + 520 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 19820304 + 37161216 = 4452^2 + 6096^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56981527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19516 + ... + 22244.

It is an arithmetic number, because the mean of its divisors is an integer number (1650285).

Almost surely, 2^56981520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 56981520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99017100).

56981520 is an abundant number, since it is smaller than the sum of its proper divisors (141052680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

56981520 is a wasteful number, since it uses less digits than its factorization.

56981520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2777 (or 2768 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 56981520 is about 7548.6104681590. The cubic root of 56981520 is about 384.8085178129.

The spelling of 56981520 in words is "fifty-six million, nine hundred eighty-one thousand, five hundred twenty".