22397581 has 2 divisors, whose sum is σ = 22397582. Its totient is φ = 22397580.

The previous prime is 22397579. The next prime is 22397587. The reversal of 22397581 is 18579322.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11964681 + 10432900 = 3459^2 + 3230^2 .

It is a cyclic number.

It is not a de Polignac number, because 22397581 - 2¹ = 22397579 is a prime.

It is a super-2 number, since 2×22397581² = 1003303269303122, which contains 22 as substring.

Together with 22397579, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 22397581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22397587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11198790 + 11198791.

It is an arithmetic number, because the mean of its divisors is an integer number (11198791).

Almost surely, 2^22397581 is an apocalyptic number.

It is an amenable number.

22397581 is a deficient number, since it is larger than the sum of its proper divisors (1).

22397581 is an equidigital number, since it uses as much as digits as its factorization.

22397581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 37.

The square root of 22397581 is about 4732.6082660622. The cubic root of 22397581 is about 281.8818016461.

The spelling of 22397581 in words is "twenty-two million, three hundred ninety-seven thousand, five hundred eighty-one".