79999920 has 640 divisors, whose sum is σ = 379975680. Its totient is φ = 14929920.

The previous prime is 79999879. The next prime is 79999973. The reversal of 79999920 is 2999997.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2162142 + ... + 2162178.

It is an arithmetic number, because the mean of its divisors is an integer number (593712).

Almost surely, 2^79999920 is an apocalyptic number.

79999920 is a gapful number since it is divisible by the number (70) 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 79999920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189987840).

79999920 is an abundant number, since it is smaller than the sum of its proper divisors (299975760).

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

79999920 is a wasteful number, since it uses less digits than its factorization.

79999920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 826686, while the sum is 54.

The square root of 79999920 is about 8944.2674378621. The cubic root of 79999920 is about 430.8867943773.

It can be divided in two parts, 79 and 999920, that added together give a palindrome (999999).

The spelling of 79999920 in words is "seventy-nine million, nine hundred ninety-nine thousand, nine hundred twenty".