23557 has 2 divisors, whose sum is σ = 23558. Its totient is φ = 23556.

The previous prime is 23549. The next prime is 23561. The reversal of 23557 is 75532.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12321 + 11236 = 111^2 + 106^2 .

It is a cyclic number.

It is not a de Polignac number, because 23557 - 2³ = 23549 is a prime.

It is a Chen prime.

It is a plaindrome in base 10.

It is a nialpdrome in base 13.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23537) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11778 + 11779.

It is an arithmetic number, because the mean of its divisors is an integer number (11779).

2²³⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

23557 is a deficient number, since it is larger than the sum of its proper divisors (1).

23557 is an equidigital number, since it uses as much as digits as its factorization.

23557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1050, while the sum is 22.

The square root of 23557 is about 153.4828980701. The cubic root of 23557 is about 28.6664112711. Note that the first 3 decimals are identical.

It can be divided in two parts, 235 and 57, that added together give a palindrome (292).

The spelling of 23557 in words is "twenty-three thousand, five hundred fifty-seven".