22221221101991 has 2 divisors, whose sum is σ = 22221221101992. Its totient is φ = 22221221101990.

The previous prime is 22221221101973. The next prime is 22221221102011. The reversal of 22221221101991 is 19910112212222.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 22221221101991 - 2¹⁴ = 22221221085607 is a prime.

It is a super-2 number, since 2×22221221101991² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22221221101951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11110610550995 + 11110610550996.

It is an arithmetic number, because the mean of its divisors is an integer number (11110610550996).

Almost surely, 2^{22221221101991} is an apocalyptic number.

22221221101991 is a deficient number, since it is larger than the sum of its proper divisors (1).

22221221101991 is an equidigital number, since it uses as much as digits as its factorization.

22221221101991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 35.

The spelling of 22221221101991 in words is "twenty-two trillion, two hundred twenty-one billion, two hundred twenty-one million, one hundred one thousand, nine hundred ninety-one".