645888375 has 192 divisors, whose sum is σ = 1390072320. Its totient is φ = 285120000.

The previous prime is 645888289. The next prime is 645888433. The reversal of 645888375 is 573888546.

It is not a de Polignac number, because 645888375 - 2⁷ = 645888247 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 9640092 + ... + 9640158.

It is an arithmetic number, because the mean of its divisors is an integer number (7239960).

Almost surely, 2^645888375 is an apocalyptic number.

645888375 is an abundant number, since it is smaller than the sum of its proper divisors (744183945).

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

645888375 is a wasteful number, since it uses less digits than its factorization.

645888375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159 (or 146 counting only the distinct ones).

The product of its digits is 6451200, while the sum is 54.

The square root of 645888375 is about 25414.3340459671. The cubic root of 645888375 is about 864.4087531893.

The spelling of 645888375 in words is "six hundred forty-five million, eight hundred eighty-eight thousand, three hundred seventy-five".