22055981 has 2 divisors, whose sum is σ = 22055982. Its totient is φ = 22055980.

The previous prime is 22055933. The next prime is 22055989. The reversal of 22055981 is 18955022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15760900 + 6295081 = 3970^2 + 2509^2 .

It is a cyclic number.

It is not a de Polignac number, because 22055981 - 2¹⁰ = 22054957 is a prime.

It is a super-2 number, since 2×22055981² = 972932595744722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22055989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11027990 + 11027991.

It is an arithmetic number, because the mean of its divisors is an integer number (11027991).

Almost surely, 2^22055981 is an apocalyptic number.

It is an amenable number.

22055981 is a deficient number, since it is larger than the sum of its proper divisors (1).

22055981 is an equidigital number, since it uses as much as digits as its factorization.

22055981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 22055981 is about 4696.3795630251. The cubic root of 22055981 is about 280.4413998876.

The spelling of 22055981 in words is "twenty-two million, fifty-five thousand, nine hundred eighty-one".