23118521 has 4 divisors (see below), whose sum is σ = 24478452. Its totient is φ = 21758592.

The previous prime is 23118517. The next prime is 23118559. The reversal of 23118521 is 12581132.

It is a happy number.

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 6431296 + 16687225 = 2536^2 + 4085^2 .

It is a cyclic number.

It is not a de Polignac number, because 23118521 - 2² = 23118517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23318521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 679940 + ... + 679973.

It is an arithmetic number, because the mean of its divisors is an integer number (6119613).

Almost surely, 2^23118521 is an apocalyptic number.

It is an amenable number.

23118521 is a deficient number, since it is larger than the sum of its proper divisors (1359931).

23118521 is a wasteful number, since it uses less digits than its factorization.

23118521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1359930.

The product of its digits is 480, while the sum is 23.

The square root of 23118521 is about 4808.1723138839. The cubic root of 23118521 is about 284.8743510969.

Adding to 23118521 its reverse (12581132), we get a palindrome (35699653).

The spelling of 23118521 in words is "twenty-three million, one hundred eighteen thousand, five hundred twenty-one".