645475 has 6 divisors (see below), whose sum is σ = 800420. Its totient is φ = 516360.

The previous prime is 645467. The next prime is 645481. The reversal of 645475 is 574546.

It is a happy number.

It is not a de Polignac number, because 645475 - 2³ = 645467 is a prime.

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 5 ways as a sum of consecutive naturals, for example, 12885 + ... + 12934.

2⁶⁴⁵⁴⁷⁵ is an apocalyptic number.

645475 is a deficient number, since it is larger than the sum of its proper divisors (154945).

645475 is a wasteful number, since it uses less digits than its factorization.

645475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25829 (or 25824 counting only the distinct ones).

The product of its digits is 16800, while the sum is 31.

The square root of 645475 is about 803.4145878686. The cubic root of 645475 is about 86.4224303760.

The spelling of 645475 in words is "six hundred forty-five thousand, four hundred seventy-five".