628640 has 24 divisors (see below), whose sum is σ = 1485540. Its totient is φ = 251392.

The previous prime is 628591. The next prime is 628651. The reversal of 628640 is 46826.

It can be written as a sum of positive squares in 2 ways, for example, as 583696 + 44944 = 764^2 + 212^2 .

It is an unprimeable number.

628640 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1805 + ... + 2124.

2⁶²⁸⁶⁴⁰ is an apocalyptic number.

It is an amenable number.

628640 is an abundant number, since it is smaller than the sum of its proper divisors (856900).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

628640 is a wasteful number, since it uses less digits than its factorization.

628640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3944 (or 3936 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 628640 is about 792.8682109910. The cubic root of 628640 is about 85.6644578119.

The spelling of 628640 in words is "six hundred twenty-eight thousand, six hundred forty".