521619968 has 20 divisors (see below), whose sum is σ = 1042222170. Its totient is φ = 260809728.

The previous prime is 521619953. The next prime is 521620009. The reversal of 521619968 is 869916125.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 503912704 + 17707264 = 22448^2 + 4208^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 508883 + ... + 509906.

Almost surely, 2^521619968 is an apocalyptic number.

It is an amenable number.

521619968 is a deficient number, since it is larger than the sum of its proper divisors (520602202).

521619968 is an equidigital number, since it uses as much as digits as its factorization.

521619968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1018807 (or 1018791 counting only the distinct ones).

The product of its digits is 233280, while the sum is 47.

The square root of 521619968 is about 22839.0010289417. The cubic root of 521619968 is about 804.9793433739.

Subtracting from 521619968 its sum of digits (47), we obtain a square (521619921 = 22839²).

The spelling of 521619968 in words is "five hundred twenty-one million, six hundred nineteen thousand, nine hundred sixty-eight".