645257475 has 24 divisors (see below), whose sum is σ = 1185363120. Its totient is φ = 344136960.

The previous prime is 645257471. The next prime is 645257507. The reversal of 645257475 is 574752546.

645257475 is a `hidden beast` number, since 6 + 4 + 5 + 2 + 574 + 75 = 666.

645257475 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 645257475 - 2² = 645257471 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 645257475.

It is not an unprimeable number, because it can be changed into a prime (645257471) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 477294 + ... + 478643.

It is an arithmetic number, because the mean of its divisors is an integer number (49390130).

Almost surely, 2^645257475 is an apocalyptic number.

645257475 is a deficient number, since it is larger than the sum of its proper divisors (540105645).

645257475 is a wasteful number, since it uses less digits than its factorization.

645257475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 955956 (or 955945 counting only the distinct ones).

The product of its digits is 1176000, while the sum is 45.

The square root of 645257475 is about 25401.9187267419. The cubic root of 645257475 is about 864.1272116895.

The spelling of 645257475 in words is "six hundred forty-five million, two hundred fifty-seven thousand, four hundred seventy-five".