23898721 has 24 divisors (see below), whose sum is σ = 30697920. Its totient is φ = 18396000.

The previous prime is 23898703. The next prime is 23898731. The reversal of 23898721 is 12789832.

It is not a de Polignac number, because 23898721 - 2¹¹ = 23896673 is a prime.

It is a super-2 number, since 2×23898721² = 1142297730871682, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (23898731) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 54220 + ... + 54658.

It is an arithmetic number, because the mean of its divisors is an integer number (1279080).

Almost surely, 2^23898721 is an apocalyptic number.

It is an amenable number.

23898721 is a deficient number, since it is larger than the sum of its proper divisors (6799199).

23898721 is a wasteful number, since it uses less digits than its factorization.

23898721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565 (or 558 counting only the distinct ones).

The product of its digits is 48384, while the sum is 40.

The square root of 23898721 is about 4888.6318126854. The cubic root of 23898721 is about 288.0435930990.

Subtracting from 23898721 its reverse (12789832), we obtain a square (11108889 = 3333²).

The spelling of 23898721 in words is "twenty-three million, eight hundred ninety-eight thousand, seven hundred twenty-one".