23145531 has 4 divisors (see below), whose sum is σ = 30860712. Its totient is φ = 15430352.

The previous prime is 23145527. The next prime is 23145533. The reversal of 23145531 is 13554132.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 23145531 - 2² = 23145527 is a prime.

It is a super-2 number, since 2×23145531² = 1071431210543922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (23145533) 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, 3857586 + ... + 3857591.

It is an arithmetic number, because the mean of its divisors is an integer number (7715178).

Almost surely, 2^23145531 is an apocalyptic number.

23145531 is a deficient number, since it is larger than the sum of its proper divisors (7715181).

23145531 is an equidigital number, since it uses as much as digits as its factorization.

23145531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7715180.

The product of its digits is 1800, while the sum is 24.

The square root of 23145531 is about 4810.9802535450. The cubic root of 23145531 is about 284.9852500831.

Adding to 23145531 its reverse (13554132), we get a palindrome (36699663).

The spelling of 23145531 in words is "twenty-three million, one hundred forty-five thousand, five hundred thirty-one".