645874 has 8 divisors (see below), whose sum is σ = 989568. Its totient is φ = 316020.

The previous prime is 645857. The next prime is 645877. The reversal of 645874 is 478546.

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

It is not an unprimeable number, because it can be changed into a prime (645877) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3342 + ... + 3529.

It is an arithmetic number, because the mean of its divisors is an integer number (123696).

2⁶⁴⁵⁸⁷⁴ is an apocalyptic number.

645874 is a deficient number, since it is larger than the sum of its proper divisors (343694).

645874 is a wasteful number, since it uses less digits than its factorization.

645874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6920.

The product of its digits is 26880, while the sum is 34.

The square root of 645874 is about 803.6628646391. The cubic root of 645874 is about 86.4402340333.

The spelling of 645874 in words is "six hundred forty-five thousand, eight hundred seventy-four".