79028665638 has 64 divisors (see below), whose sum is σ = 171983734272. Its totient is φ = 24065015040.

The previous prime is 79028665613. The next prime is 79028665657. The reversal of 79028665638 is 83656682097.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3525895 + ... + 3548237.

It is an arithmetic number, because the mean of its divisors is an integer number (2687245848).

Almost surely, 2^79028665638 is an apocalyptic number.

79028665638 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 79028665638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85991867136).

79028665638 is an abundant number, since it is smaller than the sum of its proper divisors (92955068634).

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

79028665638 is a wasteful number, since it uses less digits than its factorization.

79028665638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22829.

The product of its (nonzero) digits is 26127360, while the sum is 60.

The spelling of 79028665638 in words is "seventy-nine billion, twenty-eight million, six hundred sixty-five thousand, six hundred thirty-eight".