12221322991 has 2 divisors, whose sum is σ = 12221322992. Its totient is φ = 12221322990.

The previous prime is 12221322979. The next prime is 12221323141. The reversal of 12221322991 is 19922312221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12221322991 - 2²⁵ = 12187768559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12221322791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6110661495 + 6110661496.

It is an arithmetic number, because the mean of its divisors is an integer number (6110661496).

Almost surely, 2^12221322991 is an apocalyptic number.

12221322991 is a deficient number, since it is larger than the sum of its proper divisors (1).

12221322991 is an equidigital number, since it uses as much as digits as its factorization.

12221322991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 34.

The spelling of 12221322991 in words is "twelve billion, two hundred twenty-one million, three hundred twenty-two thousand, nine hundred ninety-one".