22640251 has 4 divisors (see below), whose sum is σ = 22757752. Its totient is φ = 22522752.

The previous prime is 22640249. The next prime is 22640269. The reversal of 22640251 is 15204622.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15204622 = 2 ⋅7602311.

It is a cyclic number.

It is not a de Polignac number, because 22640251 - 2¹ = 22640249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22640201) 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, 58461 + ... + 58846.

It is an arithmetic number, because the mean of its divisors is an integer number (5689438).

Almost surely, 2^22640251 is an apocalyptic number.

22640251 is a deficient number, since it is larger than the sum of its proper divisors (117501).

22640251 is a wasteful number, since it uses less digits than its factorization.

22640251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117500.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 22640251 is about 4758.1772770673. The cubic root of 22640251 is about 282.8961773761.

Adding to 22640251 its reverse (15204622), we get a palindrome (37844873).

The spelling of 22640251 in words is "twenty-two million, six hundred forty thousand, two hundred fifty-one".