221121199979 has 2 divisors, whose sum is σ = 221121199980. Its totient is φ = 221121199978.

The previous prime is 221121199963. The next prime is 221121200033. The reversal of 221121199979 is 979991121122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221121199979 - 2⁴ = 221121199963 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221121199979.

It is not a weakly prime, because it can be changed into another prime (221121199679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110560599989 + 110560599990.

It is an arithmetic number, because the mean of its divisors is an integer number (110560599990).

Almost surely, 2^221121199979 is an apocalyptic number.

221121199979 is a deficient number, since it is larger than the sum of its proper divisors (1).

221121199979 is an equidigital number, since it uses as much as digits as its factorization.

221121199979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 367416, while the sum is 53.

The spelling of 221121199979 in words is "two hundred twenty-one billion, one hundred twenty-one million, one hundred ninety-nine thousand, nine hundred seventy-nine".