21211102091 has 2 divisors, whose sum is σ = 21211102092. Its totient is φ = 21211102090.

The previous prime is 21211102051. The next prime is 21211102127. The reversal of 21211102091 is 19020111212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21211102091 - 2⁶ = 21211102027 is a prime.

It is not a weakly prime, because it can be changed into another prime (21211102051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605551045 + 10605551046.

It is an arithmetic number, because the mean of its divisors is an integer number (10605551046).

Almost surely, 2^21211102091 is an apocalyptic number.

21211102091 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211102091 is an equidigital number, since it uses as much as digits as its factorization.

21211102091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 20.

The spelling of 21211102091 in words is "twenty-one billion, two hundred eleven million, one hundred two thousand, ninety-one".