23660721 has 32 divisors (see below), whose sum is σ = 41809920. Its totient is φ = 12930192.

The previous prime is 23660699. The next prime is 23660743. The reversal of 23660721 is 12706632.

It is a happy number.

23660721 is a `hidden beast` number, since 2 + 36 + 607 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (23660699) and next prime (23660743).

It is not a de Polignac number, because 23660721 - 2²³ = 15272113 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (23660771) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1626 + ... + 7068.

It is an arithmetic number, because the mean of its divisors is an integer number (1306560).

Almost surely, 2^23660721 is an apocalyptic number.

23660721 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

23660721 is a deficient number, since it is larger than the sum of its proper divisors (18149199).

23660721 is a wasteful number, since it uses less digits than its factorization.

23660721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5482 (or 5476 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 23660721 is about 4864.2287158397. The cubic root of 23660721 is about 287.0842221872.

The spelling of 23660721 in words is "twenty-three million, six hundred sixty thousand, seven hundred twenty-one".