23881721 has 8 divisors (see below), whose sum is σ = 24549000. Its totient is φ = 23218560.

The previous prime is 23881717. The next prime is 23881763. The reversal of 23881721 is 12718832.

It can be written as a sum of positive squares in 4 ways, for example, as 1452025 + 22429696 = 1205^2 + 4736^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 23881721 - 2² = 23881717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23881421) 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, 13475 + ... + 15143.

It is an arithmetic number, because the mean of its divisors is an integer number (3068625).

Almost surely, 2^23881721 is an apocalyptic number.

It is an amenable number.

23881721 is a deficient number, since it is larger than the sum of its proper divisors (667279).

23881721 is a wasteful number, since it uses less digits than its factorization.

23881721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2059.

The product of its digits is 5376, while the sum is 32.

The square root of 23881721 is about 4886.8927755784. The cubic root of 23881721 is about 287.9752783885.

The spelling of 23881721 in words is "twenty-three million, eight hundred eighty-one thousand, seven hundred twenty-one".