79765921 has 16 divisors (see below), whose sum is σ = 88082640. Its totient is φ = 71895040.

The previous prime is 79765879. The next prime is 79765927. The reversal of 79765921 is 12956797.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 15124321 + 64641600 = 3889^2 + 8040^2 .

It is not a de Polignac number, because 79765921 - 2⁹ = 79765409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79765927) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66951 + ... + 68131.

It is an arithmetic number, because the mean of its divisors is an integer number (5505165).

Almost surely, 2^79765921 is an apocalyptic number.

It is an amenable number.

79765921 is a deficient number, since it is larger than the sum of its proper divisors (8316719).

79765921 is a wasteful number, since it uses less digits than its factorization.

79765921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1364.

The product of its digits is 238140, while the sum is 46.

The square root of 79765921 is about 8931.1769101278. The cubic root of 79765921 is about 430.4662708521.

The spelling of 79765921 in words is "seventy-nine million, seven hundred sixty-five thousand, nine hundred twenty-one".