521644464 has 60 divisors (see below), whose sum is σ = 1592601192. Its totient is φ = 158073600.

The previous prime is 521644451. The next prime is 521644573. The reversal of 521644464 is 464446125.

521644464 is a `hidden beast` number, since 5 + 2 + 1 + 644 + 4 + 6 + 4 = 666.

It is a super-2 number, since 2×521644464² = 544225893643694592, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 163077 + ... + 166244.

Almost surely, 2^521644464 is an apocalyptic number.

It is an amenable number.

521644464 is an abundant number, since it is smaller than the sum of its proper divisors (1070956728).

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

521644464 is a wasteful number, since it uses less digits than its factorization.

521644464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329346 (or 329337 counting only the distinct ones).

The product of its digits is 92160, while the sum is 36.

The square root of 521644464 is about 22839.5372982904. The cubic root of 521644464 is about 804.9919441602.

The spelling of 521644464 in words is "five hundred twenty-one million, six hundred forty-four thousand, four hundred sixty-four".