645956 has 12 divisors (see below), whose sum is σ = 1138368. Its totient is φ = 320712.

The previous prime is 645941. The next prime is 645973. The reversal of 645956 is 659546.

It is a happy number.

645956 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 185 + ... + 1151.

It is an arithmetic number, because the mean of its divisors is an integer number (94864).

2⁶⁴⁵⁹⁵⁶ is an apocalyptic number.

It is an amenable number.

645956 is a deficient number, since it is larger than the sum of its proper divisors (492412).

645956 is a wasteful number, since it uses less digits than its factorization.

645956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1138 (or 1136 counting only the distinct ones).

The product of its digits is 32400, while the sum is 35.

The square root of 645956 is about 803.7138794372. The cubic root of 645956 is about 86.4438920219.

The spelling of 645956 in words is "six hundred forty-five thousand, nine hundred fifty-six".