23308721 has 4 divisors (see below), whose sum is σ = 24112500. Its totient is φ = 22504944.

The previous prime is 23308673. The next prime is 23308723. The reversal of 23308721 is 12780332.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4264225 + 19044496 = 2065^2 + 4364^2 .

It is a cyclic number.

It is not a de Polignac number, because 23308721 - 2⁶ = 23308657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23308723) 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 3 ways as a sum of consecutive naturals, for example, 401846 + ... + 401903.

It is an arithmetic number, because the mean of its divisors is an integer number (6028125).

Almost surely, 2^23308721 is an apocalyptic number.

It is an amenable number.

23308721 is a deficient number, since it is larger than the sum of its proper divisors (803779).

23308721 is an equidigital number, since it uses as much as digits as its factorization.

23308721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 803778.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 23308721 is about 4827.9106246906. The cubic root of 23308721 is about 285.6534549424.

The spelling of 23308721 in words is "twenty-three million, three hundred eight thousand, seven hundred twenty-one".