21221112001091 has 2 divisors, whose sum is σ = 21221112001092. Its totient is φ = 21221112001090.

The previous prime is 21221112001087. The next prime is 21221112001097. The reversal of 21221112001091 is 19010021112212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21221112001091 - 2² = 21221112001087 is a prime.

It is not a weakly prime, because it can be changed into another prime (21221112001097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610556000545 + 10610556000546.

It is an arithmetic number, because the mean of its divisors is an integer number (10610556000546).

Almost surely, 2^{21221112001091} is an apocalyptic number.

21221112001091 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221112001091 is an equidigital number, since it uses as much as digits as its factorization.

21221112001091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 23.

The spelling of 21221112001091 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred twelve million, one thousand, ninety-one".