23011721 has 4 divisors (see below), whose sum is σ = 23043600. Its totient is φ = 22979844.

The previous prime is 23011691. The next prime is 23011733. The reversal of 23011721 is 12711032.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 23011721 - 2⁶ = 23011657 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 23011721.

It is not an unprimeable number, because it can be changed into a prime (23011771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14831 + ... + 16308.

It is an arithmetic number, because the mean of its divisors is an integer number (5760900).

Almost surely, 2^23011721 is an apocalyptic number.

It is an amenable number.

23011721 is a deficient number, since it is larger than the sum of its proper divisors (31879).

23011721 is an equidigital number, since it uses as much as digits as its factorization.

23011721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31878.

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 23011721 is about 4797.0533663907. The cubic root of 23011721 is about 284.4349984261.

Adding to 23011721 its reverse (12711032), we get a palindrome (35722753).

It can be divided in two parts, 23011 and 721, that added together give a palindrome (23732).

The spelling of 23011721 in words is "twenty-three million, eleven thousand, seven hundred twenty-one".