79999966 has 4 divisors (see below), whose sum is σ = 119999952. Its totient is φ = 39999982.

The previous prime is 79999879. The next prime is 79999973. The reversal of 79999966 is 66999997.

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

It is a junction number, because it is equal to n+sod(n) for n = 79999898 and 79999907.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19999990 + ... + 19999993.

It is an arithmetic number, because the mean of its divisors is an integer number (29999988).

Almost surely, 2^79999966 is an apocalyptic number.

79999966 is a deficient number, since it is larger than the sum of its proper divisors (39999986).

79999966 is a wasteful number, since it uses less digits than its factorization.

79999966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39999985.

The product of its digits is 14880348, while the sum is 64.

The square root of 79999966 is about 8944.2700093412. The cubic root of 79999966 is about 430.8868769641.

The spelling of 79999966 in words is "seventy-nine million, nine hundred ninety-nine thousand, nine hundred sixty-six".