21222100091 has 2 divisors, whose sum is σ = 21222100092. Its totient is φ = 21222100090.

The previous prime is 21222100087. The next prime is 21222100117. The reversal of 21222100091 is 19000122212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21222100091 - 2² = 21222100087 is a prime.

It is not a weakly prime, because it can be changed into another prime (21222106091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611050045 + 10611050046.

It is an arithmetic number, because the mean of its divisors is an integer number (10611050046).

Almost surely, 2^21222100091 is an apocalyptic number.

21222100091 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222100091 is an equidigital number, since it uses as much as digits as its factorization.

21222100091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 20.

The spelling of 21222100091 in words is "twenty-one billion, two hundred twenty-two million, one hundred thousand, ninety-one".