79221378731 has 16 divisors (see below), whose sum is σ = 91034620800. Its totient is φ = 68181912000.

The previous prime is 79221378721. The next prime is 79221378737. The reversal of 79221378731 is 13787312297.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79221378731 is a prime.

It is a super-2 number, since 2×79221378731² (a number of 23 digits) contains 22 as substring.

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 79221378731.

It is not an unprimeable number, because it can be changed into a prime (79221378737) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 175031 + ... + 434831.

It is an arithmetic number, because the mean of its divisors is an integer number (5689663800).

Almost surely, 2^79221378731 is an apocalyptic number.

79221378731 is a deficient number, since it is larger than the sum of its proper divisors (11813242069).

79221378731 is a wasteful number, since it uses less digits than its factorization.

79221378731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261290.

The product of its digits is 889056, while the sum is 50.

The spelling of 79221378731 in words is "seventy-nine billion, two hundred twenty-one million, three hundred seventy-eight thousand, seven hundred thirty-one".