23939781 has 16 divisors (see below), whose sum is σ = 33515520. Its totient is φ = 15179760.

The previous prime is 23939771. The next prime is 23939789. The reversal of 23939781 is 18793932.

It is not a de Polignac number, because 23939781 - 2⁶ = 23939717 is a prime.

It is a super-2 number, since 2×23939781² = 1146226228655922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23939789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3306 + ... + 7668.

It is an arithmetic number, because the mean of its divisors is an integer number (2094720).

Almost surely, 2^23939781 is an apocalyptic number.

It is an amenable number.

23939781 is a deficient number, since it is larger than the sum of its proper divisors (9575739).

23939781 is a wasteful number, since it uses less digits than its factorization.

23939781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4456.

The product of its digits is 81648, while the sum is 42.

The square root of 23939781 is about 4892.8295494530. The cubic root of 23939781 is about 288.2084597055.

The spelling of 23939781 in words is "twenty-three million, nine hundred thirty-nine thousand, seven hundred eighty-one".