639700 has 18 divisors (see below), whose sum is σ = 1388366. Its totient is φ = 255840.

The previous prime is 639697. The next prime is 639701. The reversal of 639700 is 7936.

It can be written as a sum of positive squares in 3 ways, for example, as 6084 + 633616 = 78^2 + 796^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639701) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3099 + ... + 3298.

2⁶³⁹⁷⁰⁰ is an apocalyptic number.

It is an amenable number.

639700 is an abundant number, since it is smaller than the sum of its proper divisors (748666).

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

639700 is a wasteful number, since it uses less digits than its factorization.

639700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6411 (or 6404 counting only the distinct ones).

The product of its (nonzero) digits is 1134, while the sum is 25.

The square root of 639700 is about 799.8124780222. The cubic root of 639700 is about 86.1639202800.

The spelling of 639700 in words is "six hundred thirty-nine thousand, seven hundred".