645231075 has 24 divisors (see below), whose sum is σ = 1113166848. Its totient is φ = 329160480.

The previous prime is 645231071. The next prime is 645231077. The reversal of 645231075 is 570132546.

645231075 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 645231075 - 2² = 645231071 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645231071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 185299 + ... + 188748.

It is an arithmetic number, because the mean of its divisors is an integer number (46381952).

Almost surely, 2^645231075 is an apocalyptic number.

645231075 is a deficient number, since it is larger than the sum of its proper divisors (467935773).

645231075 is a wasteful number, since it uses less digits than its factorization.

645231075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 374083 (or 374078 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 33.

The square root of 645231075 is about 25401.3990756415. The cubic root of 645231075 is about 864.1154265906.

The spelling of 645231075 in words is "six hundred forty-five million, two hundred thirty-one thousand, seventy-five".