22021219921 has 2 divisors, whose sum is σ = 22021219922. Its totient is φ = 22021219920.

The previous prime is 22021219907. The next prime is 22021219933. The reversal of 22021219921 is 12991212022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22018108225 + 3111696 = 148385^2 + 1764^2 .

It is a cyclic number.

It is not a de Polignac number, because 22021219921 - 2⁷ = 22021219793 is a prime.

It is not a weakly prime, because it can be changed into another prime (22021219951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11010609960 + 11010609961.

It is an arithmetic number, because the mean of its divisors is an integer number (11010609961).

Almost surely, 2^22021219921 is an apocalyptic number.

It is an amenable number.

22021219921 is a deficient number, since it is larger than the sum of its proper divisors (1).

22021219921 is an equidigital number, since it uses as much as digits as its factorization.

22021219921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 31.

The spelling of 22021219921 in words is "twenty-two billion, twenty-one million, two hundred nineteen thousand, nine hundred twenty-one".