23670721 has 2 divisors, whose sum is σ = 23670722. Its totient is φ = 23670720.

The previous prime is 23670719. The next prime is 23670737. The reversal of 23670721 is 12707632.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20657025 + 3013696 = 4545^2 + 1736^2 .

It is a cyclic number.

It is not a de Polignac number, because 23670721 - 2¹ = 23670719 is a prime.

Together with 23670719, it forms a pair of twin primes.

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

It is a self number, because there is not a number n which added to its sum of digits gives 23670721.

It is not a weakly prime, because it can be changed into another prime (23670221) 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 as a sum of consecutive naturals, namely, 11835360 + 11835361.

It is an arithmetic number, because the mean of its divisors is an integer number (11835361).

Almost surely, 2^23670721 is an apocalyptic number.

It is an amenable number.

23670721 is a deficient number, since it is larger than the sum of its proper divisors (1).

23670721 is an equidigital number, since it uses as much as digits as its factorization.

23670721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3528, while the sum is 28.

The square root of 23670721 is about 4865.2565194448. The cubic root of 23670721 is about 287.1246610488.

The spelling of 23670721 in words is "twenty-three million, six hundred seventy thousand, seven hundred twenty-one".