21221110991149 has 2 divisors, whose sum is σ = 21221110991150. Its totient is φ = 21221110991148.

The previous prime is 21221110991123. The next prime is 21221110991207. The reversal of 21221110991149 is 94119901112212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15127766850249 + 6093344140900 = 3889443^2 + 2468470^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221110991149 - 2²⁷ = 21220976773421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201110991149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610555495574 + 10610555495575.

It is an arithmetic number, because the mean of its divisors is an integer number (10610555495575).

Almost surely, 2^{21221110991149} is an apocalyptic number.

It is an amenable number.

21221110991149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221110991149 is an equidigital number, since it uses as much as digits as its factorization.

21221110991149 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 43.

The spelling of 21221110991149 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred ten million, nine hundred ninety-one thousand, one hundred forty-nine".