645664312 has 8 divisors (see below), whose sum is σ = 1210620600. Its totient is φ = 322832152.

The previous prime is 645664297. The next prime is 645664337. The reversal of 645664312 is 213466546.

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

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40354012 + ... + 40354027.

It is an arithmetic number, because the mean of its divisors is an integer number (151327575).

Almost surely, 2^645664312 is an apocalyptic number.

It is an amenable number.

645664312 is a deficient number, since it is larger than the sum of its proper divisors (564956288).

645664312 is a wasteful number, since it uses less digits than its factorization.

645664312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80708045 (or 80708041 counting only the distinct ones).

The product of its digits is 103680, while the sum is 37.

The square root of 645664312 is about 25409.9254623070. The cubic root of 645664312 is about 864.3087852347.

The spelling of 645664312 in words is "six hundred forty-five million, six hundred sixty-four thousand, three hundred twelve".