639125 has 8 divisors (see below), whose sum is σ = 797784. Its totient is φ = 511200.

The previous prime is 639091. The next prime is 639137. The reversal of 639125 is 521936.

It can be written as a sum of positive squares in 4 ways, for example, as 178084 + 461041 = 422^2 + 679^2 .

It is a de Polignac number, because none of the positive numbers 2^k-639125 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 639094 and 639103.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2432 + ... + 2681.

It is an arithmetic number, because the mean of its divisors is an integer number (99723).

2⁶³⁹¹²⁵ is an apocalyptic number.

It is an amenable number.

639125 is a deficient number, since it is larger than the sum of its proper divisors (158659).

639125 is an equidigital number, since it uses as much as digits as its factorization.

639125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5128 (or 5118 counting only the distinct ones).

The product of its digits is 1620, while the sum is 26.

The square root of 639125 is about 799.4529379519. The cubic root of 639125 is about 86.1380961405.

The spelling of 639125 in words is "six hundred thirty-nine thousand, one hundred twenty-five".