645275 has 12 divisors (see below), whose sum is σ = 816912. Its totient is φ = 505440.

The previous prime is 645257. The next prime is 645313. The reversal of 645275 is 572546.

It is not a de Polignac number, because 645275 - 2⁸ = 645019 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1082 + ... + 1568.

It is an arithmetic number, because the mean of its divisors is an integer number (68076).

2⁶⁴⁵²⁷⁵ is an apocalyptic number.

645275 is a deficient number, since it is larger than the sum of its proper divisors (171637).

645275 is a wasteful number, since it uses less digits than its factorization.

645275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550 (or 545 counting only the distinct ones).

The product of its digits is 8400, while the sum is 29.

The square root of 645275 is about 803.2901094872. The cubic root of 645275 is about 86.4135034764.

The spelling of 645275 in words is "six hundred forty-five thousand, two hundred seventy-five".