23991840 has 72 divisors (see below), whose sum is σ = 81877068. Its totient is φ = 6397440.

The previous prime is 23991839. The next prime is 23991853. The reversal of 23991840 is 4819932.

It can be written as a sum of positive squares in 2 ways, for example, as 23853456 + 138384 = 4884^2 + 372^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 23991795 and 23991804.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6891 + ... + 9770.

Almost surely, 2^23991840 is an apocalyptic number.

23991840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

23991840 is an abundant number, since it is smaller than the sum of its proper divisors (57885228).

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

23991840 is a wasteful number, since it uses less digits than its factorization.

23991840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16682 (or 16671 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 23991840 is about 4898.1465882515. The cubic root of 23991840 is about 288.4172193655.

The spelling of 23991840 in words is "twenty-three million, nine hundred ninety-one thousand, eight hundred forty".