645611026504 has 8 divisors (see below), whose sum is σ = 1210520674710. Its totient is φ = 322805513248.

The previous prime is 645611026447. The next prime is 645611026507. The reversal of 645611026504 is 405620116546.

It can be written as a sum of positive squares in only one way, i.e., 495478025604 + 150133000900 = 703902^2 + 387470^2 .

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

It is not an unprimeable number, because it can be changed into a prime (645611026507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40350689149 + ... + 40350689164.

Almost surely, 2^645611026504 is an apocalyptic number.

It is an amenable number.

645611026504 is a deficient number, since it is larger than the sum of its proper divisors (564909648206).

645611026504 is a wasteful number, since it uses less digits than its factorization.

645611026504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80701378319 (or 80701378315 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 40.

The spelling of 645611026504 in words is "six hundred forty-five billion, six hundred eleven million, twenty-six thousand, five hundred four".