79786561 has 4 divisors (see below), whose sum is σ = 79805124. Its totient is φ = 79768000.

The previous prime is 79786549. The next prime is 79786601. The reversal of 79786561 is 16568797.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 53582400 + 26204161 = 7320^2 + 5119^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79786561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79786261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 861 + ... + 12661.

It is an arithmetic number, because the mean of its divisors is an integer number (19951281).

Almost surely, 2^79786561 is an apocalyptic number.

It is an amenable number.

79786561 is a deficient number, since it is larger than the sum of its proper divisors (18563).

79786561 is a wasteful number, since it uses less digits than its factorization.

79786561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18562.

The product of its digits is 635040, while the sum is 49.

The square root of 79786561 is about 8932.3323381970. The cubic root of 79786561 is about 430.5033963876.

The spelling of 79786561 in words is "seventy-nine million, seven hundred eighty-six thousand, five hundred sixty-one".