79951999 has 4 divisors (see below), whose sum is σ = 80728336. Its totient is φ = 79175664.

The previous prime is 79951973. The next prime is 79952011. The reversal of 79951999 is 99915997.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99915997 = 419 ⋅238463.

It is a cyclic number.

It is not a de Polignac number, because 79951999 - 2²³ = 71563391 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 (79951939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 388014 + ... + 388219.

It is an arithmetic number, because the mean of its divisors is an integer number (20182084).

Almost surely, 2^79951999 is an apocalyptic number.

79951999 is a deficient number, since it is larger than the sum of its proper divisors (776337).

79951999 is a wasteful number, since it uses less digits than its factorization.

79951999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 776336.

The product of its digits is 2066715, while the sum is 58.

The square root of 79951999 is about 8941.5881698947. The cubic root of 79951999 is about 430.8007415815.

The spelling of 79951999 in words is "seventy-nine million, nine hundred fifty-one thousand, nine hundred ninety-nine".