645958 has 8 divisors (see below), whose sum is σ = 982800. Its totient is φ = 318360.

The previous prime is 645941. The next prime is 645973. The reversal of 645958 is 859546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent 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 3 ways as a sum of consecutive naturals, for example, 2133 + ... + 2416.

It is an arithmetic number, because the mean of its divisors is an integer number (122850).

2⁶⁴⁵⁹⁵⁸ is an apocalyptic number.

645958 is a deficient number, since it is larger than the sum of its proper divisors (336842).

645958 is a wasteful number, since it uses less digits than its factorization.

645958 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4622.

The product of its digits is 43200, while the sum is 37.

The square root of 645958 is about 803.7151236601. The cubic root of 645958 is about 86.4439812373.

The spelling of 645958 in words is "six hundred forty-five thousand, nine hundred fifty-eight".