645512676 has 12 divisors (see below), whose sum is σ = 1506196272. Its totient is φ = 215170888.

The previous prime is 645512671. The next prime is 645512701. The reversal of 645512676 is 676215546.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×645512676² = 833373229753361952, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (645512671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26896350 + ... + 26896373.

It is an arithmetic number, because the mean of its divisors is an integer number (125516356).

Almost surely, 2^645512676 is an apocalyptic number.

It is an amenable number.

645512676 is an abundant number, since it is smaller than the sum of its proper divisors (860683596).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645512676 is a wasteful number, since it uses less digits than its factorization.

645512676 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53792730 (or 53792728 counting only the distinct ones).

The product of its digits is 302400, while the sum is 42.

The square root of 645512676 is about 25406.9414924347. The cubic root of 645512676 is about 864.2411181897.

The spelling of 645512676 in words is "six hundred forty-five million, five hundred twelve thousand, six hundred seventy-six".