79999961 has 4 divisors (see below), whose sum is σ = 80051172. Its totient is φ = 79948752.

The previous prime is 79999879. The next prime is 79999973. The reversal of 79999961 is 16999997.

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 23088025 + 56911936 = 4805^2 + 7544^2 .

It is a cyclic number.

It is not a de Polignac number, because 79999961 - 2¹⁴ = 79983577 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 79999961.

It is not an unprimeable number, because it can be changed into a prime (79999981) 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, 23186 + ... + 26411.

It is an arithmetic number, because the mean of its divisors is an integer number (20012793).

Almost surely, 2^79999961 is an apocalyptic number.

It is an amenable number.

79999961 is a deficient number, since it is larger than the sum of its proper divisors (51211).

79999961 is a wasteful number, since it uses less digits than its factorization.

79999961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51210.

The product of its digits is 2480058, while the sum is 59.

The square root of 79999961 is about 8944.2697298326. The cubic root of 79999961 is about 430.8868679872.

It can be divided in two parts, 7999996 and 1, that added together give a palindrome (7999997).

The spelling of 79999961 in words is "seventy-nine million, nine hundred ninety-nine thousand, nine hundred sixty-one".