111221199979 has 2 divisors, whose sum is σ = 111221199980. Its totient is φ = 111221199978.

The previous prime is 111221199967. The next prime is 111221200003. The reversal of 111221199979 is 979991122111.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 111221199979 - 2¹³ = 111221191787 is a prime.

It is not a weakly prime, because it can be changed into another prime (111221199079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55610599989 + 55610599990.

It is an arithmetic number, because the mean of its divisors is an integer number (55610599990).

Almost surely, 2^111221199979 is an apocalyptic number.

111221199979 is a deficient number, since it is larger than the sum of its proper divisors (1).

111221199979 is an equidigital number, since it uses as much as digits as its factorization.

111221199979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 183708, while the sum is 52.

The spelling of 111221199979 in words is "one hundred eleven billion, two hundred twenty-one million, one hundred ninety-nine thousand, nine hundred seventy-nine".