521465640 has 64 divisors (see below), whose sum is σ = 1646740800. Its totient is φ = 131738112.

The previous prime is 521465639. The next prime is 521465647. The reversal of 521465640 is 46564125.

It is not an unprimeable number, because it can be changed into a prime (521465647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 112077 + ... + 116636.

It is an arithmetic number, because the mean of its divisors is an integer number (25730325).

Almost surely, 2^521465640 is an apocalyptic number.

It is an amenable number.

521465640 is an abundant number, since it is smaller than the sum of its proper divisors (1125275160).

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

521465640 is a wasteful number, since it uses less digits than its factorization.

521465640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228746 (or 228742 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 33.

The square root of 521465640 is about 22835.6221723867. The cubic root of 521465640 is about 804.8999477004.

The spelling of 521465640 in words is "five hundred twenty-one million, four hundred sixty-five thousand, six hundred forty".