645407564 has 12 divisors (see below), whose sum is σ = 1143760800. Its totient is φ = 318618768.

The previous prime is 645407563. The next prime is 645407573. The reversal of 645407564 is 465704546.

It is a happy number.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (645407563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1020899 + ... + 1021530.

It is an arithmetic number, because the mean of its divisors is an integer number (95313400).

Almost surely, 2^645407564 is an apocalyptic number.

It is an amenable number.

645407564 is a deficient number, since it is larger than the sum of its proper divisors (498353236).

645407564 is a wasteful number, since it uses less digits than its factorization.

645407564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2042512 (or 2042510 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 41.

The square root of 645407564 is about 25404.8728396739. The cubic root of 645407564 is about 864.1942061010.

The spelling of 645407564 in words is "six hundred forty-five million, four hundred seven thousand, five hundred sixty-four".