79993661 has 4 divisors (see below), whose sum is σ = 87265824. Its totient is φ = 72721500.

The previous prime is 79993651. The next prime is 79993663. The reversal of 79993661 is 16639997.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 79993661 - 2⁶ = 79993597 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 (79993663) 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, 3636065 + ... + 3636086.

It is an arithmetic number, because the mean of its divisors is an integer number (21816456).

Almost surely, 2^79993661 is an apocalyptic number.

It is an amenable number.

79993661 is a deficient number, since it is larger than the sum of its proper divisors (7272163).

79993661 is a wasteful number, since it uses less digits than its factorization.

79993661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7272162.

The product of its digits is 551124, while the sum is 50.

The square root of 79993661 is about 8943.9175421065. The cubic root of 79993661 is about 430.8755569045.

It can be divided in two parts, 799936 and 61, that added together give a palindrome (799997).

The spelling of 79993661 in words is "seventy-nine million, nine hundred ninety-three thousand, six hundred sixty-one".