639099968399 has 4 divisors (see below), whose sum is σ = 639169954536. Its totient is φ = 639029982264.

The previous prime is 639099968371. The next prime is 639099968503. The reversal of 639099968399 is 993869990936.

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

It is a cyclic number.

It is not a de Polignac number, because 639099968399 - 2²⁴ = 639083191183 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639099968099) 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, 34979369 + ... + 34997634.

It is an arithmetic number, because the mean of its divisors is an integer number (159792488634).

Almost surely, 2^639099968399 is an apocalyptic number.

639099968399 is a deficient number, since it is larger than the sum of its proper divisors (69986137).

639099968399 is an equidigital number, since it uses as much as digits as its factorization.

639099968399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69986136.

The product of its (nonzero) digits is 1377495072, while the sum is 80.

The spelling of 639099968399 in words is "six hundred thirty-nine billion, ninety-nine million, nine hundred sixty-eight thousand, three hundred ninety-nine".