639454233768 has 256 divisors, whose sum is σ = 1984075776000. Its totient is φ = 167815065600.

The previous prime is 639454233749. The next prime is 639454233787. The reversal of 639454233768 is 867332454936.

It is an interprime number because it is at equal distance from previous prime (639454233749) and next prime (639454233787).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8875008 + ... + 8946768.

It is an arithmetic number, because the mean of its divisors is an integer number (7750296000).

Almost surely, 2^639454233768 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639454233768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (992037888000).

639454233768 is an abundant number, since it is smaller than the sum of its proper divisors (1344621542232).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

639454233768 is a wasteful number, since it uses less digits than its factorization.

639454233768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71896 (or 71892 counting only the distinct ones).

The product of its digits is 78382080, while the sum is 60.

The spelling of 639454233768 in words is "six hundred thirty-nine billion, four hundred fifty-four million, two hundred thirty-three thousand, seven hundred sixty-eight".