79969999 has 4 divisors (see below), whose sum is σ = 80052336. Its totient is φ = 79887664.

The previous prime is 79969997. The next prime is 79970029. The reversal of 79969999 is 99996997.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99996997 = 593 ⋅168629.

It is a cyclic number.

It is not a de Polignac number, because 79969999 - 2¹ = 79969997 is a prime.

It is a Duffinian number.

79969999 is a modest number, since divided by 9999 gives 7996 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79969997) 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, 39694 + ... + 41659.

It is an arithmetic number, because the mean of its divisors is an integer number (20013084).

Almost surely, 2^79969999 is an apocalyptic number.

79969999 is a deficient number, since it is larger than the sum of its proper divisors (82337).

79969999 is an equidigital number, since it uses as much as digits as its factorization.

79969999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82336.

The product of its digits is 22320522, while the sum is 67.

The square root of 79969999 is about 8942.5946458508. The cubic root of 79969999 is about 430.8330686093.

The spelling of 79969999 in words is "seventy-nine million, nine hundred sixty-nine thousand, nine hundred ninety-nine".