22811993 has 2 divisors, whose sum is σ = 22811994. Its totient is φ = 22811992.

The previous prime is 22811981. The next prime is 22812019. The reversal of 22811993 is 39911822.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20403289 + 2408704 = 4517^2 + 1552^2 .

It is a cyclic number.

It is not a de Polignac number, because 22811993 - 2²² = 18617689 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (22811923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11405996 + 11405997.

It is an arithmetic number, because the mean of its divisors is an integer number (11405997).

Almost surely, 2^22811993 is an apocalyptic number.

It is an amenable number.

22811993 is a deficient number, since it is larger than the sum of its proper divisors (1).

22811993 is an equidigital number, since it uses as much as digits as its factorization.

22811993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 35.

The square root of 22811993 is about 4776.1902181551. The cubic root of 22811993 is about 283.6096974356.

It can be divided in two parts, 228 and 11993, that added together give a palindrome (12221).

The spelling of 22811993 in words is "twenty-two million, eight hundred eleven thousand, nine hundred ninety-three".