639125859 has 4 divisors (see below), whose sum is σ = 852167816. Its totient is φ = 426083904.

The previous prime is 639125843. The next prime is 639125951. The reversal of 639125859 is 958521936.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 639125859 - 2⁴ = 639125843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639125759) 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, 106520974 + ... + 106520979.

It is an arithmetic number, because the mean of its divisors is an integer number (213041954).

Almost surely, 2^639125859 is an apocalyptic number.

639125859 is a deficient number, since it is larger than the sum of its proper divisors (213041957).

639125859 is a wasteful number, since it uses less digits than its factorization.

639125859 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213041956.

The product of its digits is 583200, while the sum is 48.

The square root of 639125859 is about 25280.9386495043. The cubic root of 639125859 is about 861.3813473110.

The spelling of 639125859 in words is "six hundred thirty-nine million, one hundred twenty-five thousand, eight hundred fifty-nine".