79999665408 has 432 divisors, whose sum is σ = 265345866240. Its totient is φ = 22992076800.

The previous prime is 79999665367. The next prime is 79999665409. The reversal of 79999665408 is 80456699997.

79999665408 is a `hidden beast` number, since 79 + 9 + 9 + 9 + 6 + 6 + 540 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79999665409) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 26925363 + ... + 26928333.

Almost surely, 2^79999665408 is an apocalyptic number.

79999665408 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 79999665408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132672933120).

79999665408 is an abundant number, since it is smaller than the sum of its proper divisors (185346200832).

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

79999665408 is a wasteful number, since it uses less digits than its factorization.

79999665408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3066 (or 3049 counting only the distinct ones).

The product of its (nonzero) digits is 264539520, while the sum is 72.

The spelling of 79999665408 in words is "seventy-nine billion, nine hundred ninety-nine million, six hundred sixty-five thousand, four hundred eight".