521699540 has 12 divisors (see below), whose sum is σ = 1095569076. Its totient is φ = 208679808.

The previous prime is 521699533. The next prime is 521699543. The reversal of 521699540 is 45996125.

It can be written as a sum of positive squares in 2 ways, for example, as 236359876 + 285339664 = 15374^2 + 16892^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521699543) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13042469 + ... + 13042508.

It is an arithmetic number, because the mean of its divisors is an integer number (91297423).

Almost surely, 2^521699540 is an apocalyptic number.

It is an amenable number.

521699540 is an abundant number, since it is smaller than the sum of its proper divisors (573869536).

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

521699540 is a wasteful number, since it uses less digits than its factorization.

521699540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26084986 (or 26084984 counting only the distinct ones).

The product of its (nonzero) digits is 97200, while the sum is 41.

The square root of 521699540 is about 22840.7429826615. The cubic root of 521699540 is about 805.0202739130.

The spelling of 521699540 in words is "five hundred twenty-one million, six hundred ninety-nine thousand, five hundred forty".