23406721 has 8 divisors (see below), whose sum is σ = 25245864. Its totient is φ = 21573120.

The previous prime is 23406701. The next prime is 23406731. The reversal of 23406721 is 12760432.

It can be written as a sum of positive squares in 4 ways, for example, as 6890625 + 16516096 = 2625^2 + 4064^2 .

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 23406721 - 2¹⁵ = 23373953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23406701) 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, 12945 + ... + 14641.

It is an arithmetic number, because the mean of its divisors is an integer number (3155733).

Almost surely, 2^23406721 is an apocalyptic number.

It is an amenable number.

23406721 is a deficient number, since it is larger than the sum of its proper divisors (1839143).

23406721 is a wasteful number, since it uses less digits than its factorization.

23406721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2771.

The product of its (nonzero) digits is 2016, while the sum is 25.

The square root of 23406721 is about 4838.0492969791. The cubic root of 23406721 is about 286.0532323038.

The spelling of 23406721 in words is "twenty-three million, four hundred six thousand, seven hundred twenty-one".