645169678 has 16 divisors (see below), whose sum is σ = 991028016. Its totient is φ = 314838720.

The previous prime is 645169631. The next prime is 645169691. The reversal of 645169678 is 876961546.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164298 + ... + 168178.

It is an arithmetic number, because the mean of its divisors is an integer number (61939251).

Almost surely, 2^645169678 is an apocalyptic number.

645169678 is a deficient number, since it is larger than the sum of its proper divisors (345858338).

645169678 is a wasteful number, since it uses less digits than its factorization.

645169678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5859.

The product of its digits is 2177280, while the sum is 52.

The square root of 645169678 is about 25400.1905110966. The cubic root of 645169678 is about 864.0880174035.

The spelling of 645169678 in words is "six hundred forty-five million, one hundred sixty-nine thousand, six hundred seventy-eight".