22657991 has 4 divisors (see below), whose sum is σ = 23990832. Its totient is φ = 21325152.

The previous prime is 22657963. The next prime is 22657997. The reversal of 22657991 is 19975622.

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 22657991 - 2⁶ = 22657927 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 (22657997) 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, 666395 + ... + 666428.

It is an arithmetic number, because the mean of its divisors is an integer number (5997708).

Almost surely, 2^22657991 is an apocalyptic number.

22657991 is a deficient number, since it is larger than the sum of its proper divisors (1332841).

22657991 is a wasteful number, since it uses less digits than its factorization.

22657991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1332840.

The product of its digits is 68040, while the sum is 41.

The square root of 22657991 is about 4760.0410712514. The cubic root of 22657991 is about 282.9700468159.

The spelling of 22657991 in words is "twenty-two million, six hundred fifty-seven thousand, nine hundred ninety-one".