639581313 has 8 divisors (see below), whose sum is σ = 974600128. Its totient is φ = 365475024.

The previous prime is 639581233. The next prime is 639581333. The reversal of 639581313 is 313185936.

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

It is not a de Polignac number, because 639581313 - 2¹⁰ = 639580289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639581333) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15228106 + ... + 15228147.

It is an arithmetic number, because the mean of its divisors is an integer number (121825016).

Almost surely, 2^639581313 is an apocalyptic number.

It is an amenable number.

639581313 is a deficient number, since it is larger than the sum of its proper divisors (335018815).

639581313 is a wasteful number, since it uses less digits than its factorization.

639581313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30456263.

The product of its digits is 58320, while the sum is 39.

The square root of 639581313 is about 25289.9448991096. The cubic root of 639581313 is about 861.5859113103.

The spelling of 639581313 in words is "six hundred thirty-nine million, five hundred eighty-one thousand, three hundred thirteen".