23640040 has 32 divisors (see below), whose sum is σ = 54631080. Its totient is φ = 9199872.

The previous prime is 23640037. The next prime is 23640049. The reversal of 23640040 is 4004632.

It can be written as a sum of positive squares in 4 ways, for example, as 23367556 + 272484 = 4834^2 + 522^2 .

It is not an unprimeable number, because it can be changed into a prime (23640049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6507 + ... + 9466.

Almost surely, 2^23640040 is an apocalyptic number.

23640040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

23640040 is an abundant number, since it is smaller than the sum of its proper divisors (30991040).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

23640040 is a wasteful number, since it uses less digits than its factorization.

23640040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16021 (or 16017 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 23640040 is about 4862.1024259059. The cubic root of 23640040 is about 287.0005544146. Note that the first 3 decimals are identical.

Adding to 23640040 its reverse (4004632), we get a palindrome (27644672).

The spelling of 23640040 in words is "twenty-three million, six hundred forty thousand, forty".