22528991 has 2 divisors, whose sum is σ = 22528992. Its totient is φ = 22528990.

The previous prime is 22528963. The next prime is 22528999. The reversal of 22528991 is 19982522.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22528991 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22528999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11264495 + 11264496.

It is an arithmetic number, because the mean of its divisors is an integer number (11264496).

Almost surely, 2^22528991 is an apocalyptic number.

22528991 is a deficient number, since it is larger than the sum of its proper divisors (1).

22528991 is an equidigital number, since it uses as much as digits as its factorization.

22528991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 38.

The square root of 22528991 is about 4746.4714262281. The cubic root of 22528991 is about 282.4320080712.

Multiplying 22528991 by its sum of digits (38), we get a palindrome (856101658).

The spelling of 22528991 in words is "twenty-two million, five hundred twenty-eight thousand, nine hundred ninety-one".