639758083021 has 12 divisors (see below), whose sum is σ = 709152640992. Its totient is φ = 575945889728.

The previous prime is 639758083009. The next prime is 639758083033. The reversal of 639758083021 is 120380857936.

It is an interprime number because it is at equal distance from previous prime (639758083009) and next prime (639758083033).

It is not a de Polignac number, because 639758083021 - 2⁵ = 639758082989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 639758083021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639758083051) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 48117175 + ... + 48130468.

It is an arithmetic number, because the mean of its divisors is an integer number (59096053416).

Almost surely, 2^639758083021 is an apocalyptic number.

It is an amenable number.

639758083021 is a deficient number, since it is larger than the sum of its proper divisors (69394557971).

639758083021 is a wasteful number, since it uses less digits than its factorization.

639758083021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96247700 (or 96247683 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 52.

The spelling of 639758083021 in words is "six hundred thirty-nine billion, seven hundred fifty-eight million, eighty-three thousand, twenty-one".