521713668 has 48 divisors (see below), whose sum is σ = 1423600640. Its totient is φ = 145593504.

The previous prime is 521713649. The next prime is 521713679. The reversal of 521713668 is 866317125.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68608 + ... + 75831.

Almost surely, 2^521713668 is an apocalyptic number.

It is an amenable number.

521713668 is an abundant number, since it is smaller than the sum of its proper divisors (901886972).

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

521713668 is a wasteful number, since it uses less digits than its factorization.

521713668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144496 (or 144494 counting only the distinct ones).

The product of its digits is 60480, while the sum is 39.

The square root of 521713668 is about 22841.0522524686. The cubic root of 521713668 is about 805.0275406907.

The spelling of 521713668 in words is "five hundred twenty-one million, seven hundred thirteen thousand, six hundred sixty-eight".