22640491 has 4 divisors (see below), whose sum is σ = 22913352. Its totient is φ = 22367632.

The previous prime is 22640477. The next prime is 22640539. The reversal of 22640491 is 19404622.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19404622 = 2 ⋅9702311.

It is a cyclic number.

It is not a de Polignac number, because 22640491 - 2⁷ = 22640363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22640461) 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, 136306 + ... + 136471.

It is an arithmetic number, because the mean of its divisors is an integer number (5728338).

Almost surely, 2^22640491 is an apocalyptic number.

22640491 is a deficient number, since it is larger than the sum of its proper divisors (272861).

22640491 is an equidigital number, since it uses as much as digits as its factorization.

22640491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272860.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 22640491 is about 4758.2024967418. The cubic root of 22640491 is about 282.8971769947.

The spelling of 22640491 in words is "twenty-two million, six hundred forty thousand, four hundred ninety-one".