79758721 has 6 divisors (see below), whose sum is σ = 92780610. Its totient is φ = 68364576.

The previous prime is 79758719. The next prime is 79758761. The reversal of 79758721 is 12785797.

It can be written as a sum of positive squares in only one way, i.e., 76317696 + 3441025 = 8736^2 + 1855^2 .

It is not a de Polignac number, because 79758721 - 2¹ = 79758719 is a prime.

It is a super-2 number, since 2×79758721² = 12722907151111682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79758761) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 813816 + ... + 813913.

It is an arithmetic number, because the mean of its divisors is an integer number (15463435).

Almost surely, 2^79758721 is an apocalyptic number.

It is an amenable number.

79758721 is a deficient number, since it is larger than the sum of its proper divisors (13021889).

79758721 is a wasteful number, since it uses less digits than its factorization.

79758721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1627743 (or 1627736 counting only the distinct ones).

The product of its digits is 246960, while the sum is 46.

The square root of 79758721 is about 8930.7738186565. The cubic root of 79758721 is about 430.4533185772.

The spelling of 79758721 in words is "seventy-nine million, seven hundred fifty-eight thousand, seven hundred twenty-one".