521165056 has 72 divisors (see below), whose sum is σ = 1137314304. Its totient is φ = 237281280.

The previous prime is 521165009. The next prime is 521165069. The reversal of 521165056 is 650561125.

It is a super-2 number, since 2×521165056² = 543226031190966272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132981 + ... + 136843.

It is an arithmetic number, because the mean of its divisors is an integer number (15796032).

Almost surely, 2^521165056 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 521165056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (568657152).

521165056 is an abundant number, since it is smaller than the sum of its proper divisors (616149248).

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

521165056 is a wasteful number, since it uses less digits than its factorization.

521165056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3927 (or 3913 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 31.

The square root of 521165056 is about 22829.0397520351. The cubic root of 521165056 is about 804.7452641005.

The spelling of 521165056 in words is "five hundred twenty-one million, one hundred sixty-five thousand, fifty-six".