521639690 has 64 divisors (see below), whose sum is σ = 1133032320. Its totient is φ = 170346240.

The previous prime is 521639687. The next prime is 521639707. The reversal of 521639690 is 96936125.

It is a super-2 number, since 2×521639690² = 544215932366592200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 47981 + ... + 57839.

It is an arithmetic number, because the mean of its divisors is an integer number (17703630).

Almost surely, 2^521639690 is an apocalyptic number.

521639690 is an abundant number, since it is smaller than the sum of its proper divisors (611392630).

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

521639690 is a wasteful number, since it uses less digits than its factorization.

521639690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9927.

The product of its (nonzero) digits is 87480, while the sum is 41.

The square root of 521639690 is about 22839.4327863019. The cubic root of 521639690 is about 804.9894884370.

The spelling of 521639690 in words is "five hundred twenty-one million, six hundred thirty-nine thousand, six hundred ninety".