2222222121991 has 2 divisors, whose sum is σ = 2222222121992. Its totient is φ = 2222222121990.

The previous prime is 2222222121961. The next prime is 2222222122009. The reversal of 2222222121991 is 1991212222222.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2222222121991 - 2⁷ = 2222222121863 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2222222121991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2222222121901) 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 as a sum of consecutive naturals, namely, 1111111060995 + 1111111060996.

It is an arithmetic number, because the mean of its divisors is an integer number (1111111060996).

Almost surely, 2^{2222222121991} is an apocalyptic number.

2222222121991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2222222121991 is an equidigital number, since it uses as much as digits as its factorization.

2222222121991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 37.

The spelling of 2222222121991 in words is "two trillion, two hundred twenty-two billion, two hundred twenty-two million, one hundred twenty-one thousand, nine hundred ninety-one".