20221211100991 has 2 divisors, whose sum is σ = 20221211100992. Its totient is φ = 20221211100990.

The previous prime is 20221211100983. The next prime is 20221211101019. The reversal of 20221211100991 is 19900111212202.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20221211100991 - 2³ = 20221211100983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20221211100941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10110605550495 + 10110605550496.

It is an arithmetic number, because the mean of its divisors is an integer number (10110605550496).

Almost surely, 2^{20221211100991} is an apocalyptic number.

20221211100991 is a deficient number, since it is larger than the sum of its proper divisors (1).

20221211100991 is an equidigital number, since it uses as much as digits as its factorization.

20221211100991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 31.

The spelling of 20221211100991 in words is "twenty trillion, two hundred twenty-one billion, two hundred eleven million, one hundred thousand, nine hundred ninety-one".