645634636 has 12 divisors (see below), whose sum is σ = 1196323128. Its totient is φ = 303828032.

The previous prime is 645634621. The next prime is 645634651. The reversal of 645634636 is 636436546.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (645634621) and next prime (645634651).

It is a junction number, because it is equal to n+sod(n) for n = 645634592 and 645634601.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4747246 + ... + 4747381.

It is an arithmetic number, because the mean of its divisors is an integer number (99693594).

Almost surely, 2^645634636 is an apocalyptic number.

It is an amenable number.

645634636 is a deficient number, since it is larger than the sum of its proper divisors (550688492).

645634636 is a wasteful number, since it uses less digits than its factorization.

645634636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9494648 (or 9494646 counting only the distinct ones).

The product of its digits is 933120, while the sum is 43.

The square root of 645634636 is about 25409.3415105547. The cubic root of 645634636 is about 864.2955432553.

The spelling of 645634636 in words is "six hundred forty-five million, six hundred thirty-four thousand, six hundred thirty-six".