23640251 has 16 divisors (see below), whose sum is σ = 26417664. Its totient is φ = 21039744.

The previous prime is 23640241. The next prime is 23640257. The reversal of 23640251 is 15204632.

23640251 = 231² + 232² + ... + 436².

It is not a de Polignac number, because 23640251 - 2¹⁴ = 23623867 is a prime.

It is a super-2 number, since 2×23640251² = 1117722934686002, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23640257) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39980 + ... + 40566.

It is an arithmetic number, because the mean of its divisors is an integer number (1651104).

Almost surely, 2^23640251 is an apocalyptic number.

23640251 is a deficient number, since it is larger than the sum of its proper divisors (2777413).

23640251 is a wasteful number, since it uses less digits than its factorization.

23640251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 730.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 23640251 is about 4862.1241242897. The cubic root of 23640251 is about 287.0014082899.

Adding to 23640251 its reverse (15204632), we get a palindrome (38844883).

The spelling of 23640251 in words is "twenty-three million, six hundred forty thousand, two hundred fifty-one".