111111999979 has 2 divisors, whose sum is σ = 111111999980. Its totient is φ = 111111999978.

The previous prime is 111111999961. The next prime is 111112000009. The reversal of 111111999979 is 979999111111.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111111999979 is a prime.

It is a super-3 number, since 3×111111999979³ (a number of 34 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (111111999919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55555999989 + 55555999990.

It is an arithmetic number, because the mean of its divisors is an integer number (55555999990).

Almost surely, 2^111111999979 is an apocalyptic number.

111111999979 is a deficient number, since it is larger than the sum of its proper divisors (1).

111111999979 is an equidigital number, since it uses as much as digits as its factorization.

111111999979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 413343, while the sum is 58.

The spelling of 111111999979 in words is "one hundred eleven billion, one hundred eleven million, nine hundred ninety-nine thousand, nine hundred seventy-nine".