22908991 has 4 divisors (see below), whose sum is σ = 26181712. Its totient is φ = 19636272.

The previous prime is 22908983. The next prime is 22909001. The reversal of 22908991 is 19980922.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 22908991 - 2³ = 22908983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22908901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1636350 + ... + 1636363.

It is an arithmetic number, because the mean of its divisors is an integer number (6545428).

Almost surely, 2^22908991 is an apocalyptic number.

22908991 is a deficient number, since it is larger than the sum of its proper divisors (3272721).

22908991 is an equidigital number, since it uses as much as digits as its factorization.

22908991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3272720.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 22908991 is about 4786.3337744040. Note that the first 3 decimals coincide. The cubic root of 22908991 is about 284.0111043400.

The spelling of 22908991 in words is "twenty-two million, nine hundred eight thousand, nine hundred ninety-one".