645807167640 has 96 divisors (see below), whose sum is σ = 2222336450880. Its totient is φ = 162084934656.

The previous prime is 645807167627. The next prime is 645807167669. The reversal of 645807167640 is 46761708546.

645807167640 is a `hidden beast` number, since 6 + 4 + 580 + 7 + 16 + 7 + 6 + 40 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 52755904 + ... + 52768143.

It is an arithmetic number, because the mean of its divisors is an integer number (23149338030).

Almost surely, 2^645807167640 is an apocalyptic number.

645807167640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

645807167640 is an abundant number, since it is smaller than the sum of its proper divisors (1576529283240).

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

645807167640 is a wasteful number, since it uses less digits than its factorization.

645807167640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105524081 (or 105524074 counting only the distinct ones).

The product of its (nonzero) digits is 6773760, while the sum is 54.

The spelling of 645807167640 in words is "six hundred forty-five billion, eight hundred seven million, one hundred sixty-seven thousand, six hundred forty".