521370664 has 8 divisors (see below), whose sum is σ = 977570010. Its totient is φ = 260685328.

The previous prime is 521370611. The next prime is 521370677. The reversal of 521370664 is 466073125.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 512116900 + 9253764 = 22630^2 + 3042^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32585659 + ... + 32585674.

Almost surely, 2^521370664 is an apocalyptic number.

It is an amenable number.

521370664 is a deficient number, since it is larger than the sum of its proper divisors (456199346).

521370664 is a wasteful number, since it uses less digits than its factorization.

521370664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65171339 (or 65171335 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 521370664 is about 22833.5425197230. The cubic root of 521370664 is about 804.8510785049.

The spelling of 521370664 in words is "five hundred twenty-one million, three hundred seventy thousand, six hundred sixty-four".