22991257 has 4 divisors (see below), whose sum is σ = 23043600. Its totient is φ = 22938916.

The previous prime is 22991233. The next prime is 22991299. The reversal of 22991257 is 75219922.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75219922 = 2 ⋅37609961.

It is a cyclic number.

It is not a de Polignac number, because 22991257 - 2¹¹ = 22989209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22991207) 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, 25507 + ... + 26392.

It is an arithmetic number, because the mean of its divisors is an integer number (5760900).

Almost surely, 2^22991257 is an apocalyptic number.

It is an amenable number.

22991257 is a deficient number, since it is larger than the sum of its proper divisors (52343).

22991257 is an equidigital number, since it uses as much as digits as its factorization.

22991257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52342.

The product of its digits is 22680, while the sum is 37.

The square root of 22991257 is about 4794.9199159110. The cubic root of 22991257 is about 284.3506587385.

The spelling of 22991257 in words is "twenty-two million, nine hundred ninety-one thousand, two hundred fifty-seven".