79791661 has 4 divisors (see below), whose sum is σ = 79828924. Its totient is φ = 79754400.

The previous prime is 79791641. The next prime is 79791667. The reversal of 79791661 is 16619797.

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 46498761 + 33292900 = 6819^2 + 5770^2 .

It is a cyclic number.

It is not a de Polignac number, because 79791661 - 2⁵ = 79791629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79791667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15210 + ... + 19771.

It is an arithmetic number, because the mean of its divisors is an integer number (19957231).

Almost surely, 2^79791661 is an apocalyptic number.

It is an amenable number.

79791661 is a deficient number, since it is larger than the sum of its proper divisors (37263).

79791661 is a wasteful number, since it uses less digits than its factorization.

79791661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37262.

The product of its digits is 142884, while the sum is 46.

The square root of 79791661 is about 8932.6178133848. The cubic root of 79791661 is about 430.5125688619.

The spelling of 79791661 in words is "seventy-nine million, seven hundred ninety-one thousand, six hundred sixty-one".