22121211997 has 2 divisors, whose sum is σ = 22121211998. Its totient is φ = 22121211996.

The previous prime is 22121211953. The next prime is 22121212007. The reversal of 22121211997 is 79911212122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14317079716 + 7804132281 = 119654^2 + 88341^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22121211997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22121217997) 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, 11060605998 + 11060605999.

It is an arithmetic number, because the mean of its divisors is an integer number (11060605999).

Almost surely, 2^22121211997 is an apocalyptic number.

It is an amenable number.

22121211997 is a deficient number, since it is larger than the sum of its proper divisors (1).

22121211997 is an equidigital number, since it uses as much as digits as its factorization.

22121211997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 37.

The spelling of 22121211997 in words is "twenty-two billion, one hundred twenty-one million, two hundred eleven thousand, nine hundred ninety-seven".