23123561 has 4 divisors (see below), whose sum is σ = 23133252. Its totient is φ = 23113872.

The previous prime is 23123521. The next prime is 23123563. The reversal of 23123561 is 16532132.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 7123561 + 16000000 = 2669^2 + 4000^2 .

It is a cyclic number.

It is not a de Polignac number, because 23123561 - 2⁶ = 23123497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23123563) 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, 1535 + ... + 6971.

It is an arithmetic number, because the mean of its divisors is an integer number (5783313).

Almost surely, 2^23123561 is an apocalyptic number.

It is an amenable number.

23123561 is a deficient number, since it is larger than the sum of its proper divisors (9691).

23123561 is an equidigital number, since it uses as much as digits as its factorization.

23123561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9690.

The product of its digits is 1080, while the sum is 23.

The square root of 23123561 is about 4808.6963929947. The cubic root of 23123561 is about 284.8950511294.

Adding to 23123561 its reverse (16532132), we get a palindrome (39655693).

The spelling of 23123561 in words is "twenty-three million, one hundred twenty-three thousand, five hundred sixty-one".