111207979721 has 4 divisors (see below), whose sum is σ = 111210224592. Its totient is φ = 111205734852.

The previous prime is 111207979711. The next prime is 111207979747. The reversal of 111207979721 is 127979702111.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111207979721 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (111207979711) 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, 1046411 + ... + 1147776.

It is an arithmetic number, because the mean of its divisors is an integer number (27802556148).

Almost surely, 2^111207979721 is an apocalyptic number.

It is an amenable number.

111207979721 is a deficient number, since it is larger than the sum of its proper divisors (2244871).

111207979721 is an equidigital number, since it uses as much as digits as its factorization.

111207979721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2244870.

The product of its (nonzero) digits is 111132, while the sum is 47.

The spelling of 111207979721 in words is "one hundred eleven billion, two hundred seven million, nine hundred seventy-nine thousand, seven hundred twenty-one".