639074391 has 8 divisors (see below), whose sum is σ = 852217344. Its totient is φ = 425990520.

The previous prime is 639074357. The next prime is 639074399. The reversal of 639074391 is 193470936.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-639074391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639074399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29020 + ... + 46046.

It is an arithmetic number, because the mean of its divisors is an integer number (106527168).

Almost surely, 2^639074391 is an apocalyptic number.

639074391 is a deficient number, since it is larger than the sum of its proper divisors (213142953).

639074391 is a wasteful number, since it uses less digits than its factorization.

639074391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29541.

The product of its (nonzero) digits is 122472, while the sum is 42.

The square root of 639074391 is about 25279.9207079453. The cubic root of 639074391 is about 861.3582247055.

The spelling of 639074391 in words is "six hundred thirty-nine million, seventy-four thousand, three hundred ninety-one".