23555221 has 4 divisors (see below), whose sum is σ = 24367500. Its totient is φ = 22742944.

The previous prime is 23555179. The next prime is 23555237. The reversal of 23555221 is 12255532.

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 4536900 + 19018321 = 2130^2 + 4361^2 .

It is a cyclic number.

It is not a de Polignac number, because 23555221 - 2²¹ = 21458069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23555281) 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, 406096 + ... + 406153.

It is an arithmetic number, because the mean of its divisors is an integer number (6091875).

Almost surely, 2^23555221 is an apocalyptic number.

It is an amenable number.

23555221 is a deficient number, since it is larger than the sum of its proper divisors (812279).

23555221 is an equidigital number, since it uses as much as digits as its factorization.

23555221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 812278.

The product of its digits is 3000, while the sum is 25.

The square root of 23555221 is about 4853.3721266765. The cubic root of 23555221 is about 286.6568963379.

The spelling of 23555221 in words is "twenty-three million, five hundred fifty-five thousand, two hundred twenty-one".