645375 has 16 divisors (see below), whose sum is σ = 1074528. Its totient is φ = 344000.

The previous prime is 645367. The next prime is 645383. The reversal of 645375 is 573546.

It is an interprime number because it is at equal distance from previous prime (645367) and next prime (645383).

It is not a de Polignac number, because 645375 - 2³ = 645367 is a prime.

645375 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 486 + ... + 1235.

It is an arithmetic number, because the mean of its divisors is an integer number (67158).

2⁶⁴⁵³⁷⁵ is an apocalyptic number.

645375 is a deficient number, since it is larger than the sum of its proper divisors (429153).

645375 is a wasteful number, since it uses less digits than its factorization.

645375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1739 (or 1729 counting only the distinct ones).

The product of its digits is 12600, while the sum is 30.

The square root of 645375 is about 803.3523510889. The cubic root of 645375 is about 86.4179671568.

The spelling of 645375 in words is "six hundred forty-five thousand, three hundred seventy-five".