23172555 has 32 divisors (see below), whose sum is σ = 42624000. Its totient is φ = 10530432.

The previous prime is 23172529. The next prime is 23172557. The reversal of 23172555 is 55527132.

23172555 = T₈₂₆ + T₈₂₇ + ... + T₈₈₈.

It is not a de Polignac number, because 23172555 - 2²⁰ = 22123979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (23172557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20341 + ... + 21449.

It is an arithmetic number, because the mean of its divisors is an integer number (1332000).

Almost surely, 2^23172555 is an apocalyptic number.

23172555 is a deficient number, since it is larger than the sum of its proper divisors (19451445).

23172555 is a wasteful number, since it uses less digits than its factorization.

23172555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323.

The product of its digits is 10500, while the sum is 30.

The square root of 23172555 is about 4813.7880094578. The cubic root of 23172555 is about 285.0961202408.

Adding to 23172555 its reverse (55527132), we get a palindrome (78699687).

It can be divided in two parts, 23 and 172555, that added together give a triangular number (172578 = T₅₈₇).

The spelling of 23172555 in words is "twenty-three million, one hundred seventy-two thousand, five hundred fifty-five".