23133221 has 4 divisors (see below), whose sum is σ = 23143500. Its totient is φ = 23122944.

The previous prime is 23133199. The next prime is 23133263. The reversal of 23133221 is 12233132.

23133221 is nontrivially palindromic in base 4.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 15124321 + 8008900 = 3889^2 + 2830^2 .

It is a cyclic number.

It is not a de Polignac number, because 23133221 - 2¹⁸ = 22871077 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 23133221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23136221) 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, 146 + ... + 6803.

It is an arithmetic number, because the mean of its divisors is an integer number (5785875).

Almost surely, 2^23133221 is an apocalyptic number.

It is an amenable number.

23133221 is a deficient number, since it is larger than the sum of its proper divisors (10279).

23133221 is an equidigital number, since it uses as much as digits as its factorization.

23133221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10278.

The product of its digits is 216, while the sum is 17.

The square root of 23133221 is about 4809.7007183400. The cubic root of 23133221 is about 284.9347177859.

Adding to 23133221 its reverse (12233132), we get a palindrome (35366353).

The spelling of 23133221 in words is "twenty-three million, one hundred thirty-three thousand, two hundred twenty-one".