639875901 has 16 divisors (see below), whose sum is σ = 1026368000. Its totient is φ = 346398768.

The previous prime is 639875851. The next prime is 639875921. The reversal of 639875901 is 109578936.

It is not a de Polignac number, because 639875901 - 2¹⁰ = 639874877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639875921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 801451 + ... + 802248.

It is an arithmetic number, because the mean of its divisors is an integer number (64148000).

Almost surely, 2^639875901 is an apocalyptic number.

It is an amenable number.

639875901 is a deficient number, since it is larger than the sum of its proper divisors (386492099).

639875901 is a wasteful number, since it uses less digits than its factorization.

639875901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1603728.

The product of its (nonzero) digits is 408240, while the sum is 48.

The square root of 639875901 is about 25295.7684405910. The cubic root of 639875901 is about 861.7181717475.

The spelling of 639875901 in words is "six hundred thirty-nine million, eight hundred seventy-five thousand, nine hundred one".