23215221 has 8 divisors (see below), whose sum is σ = 34392960. Its totient is φ = 15476796.

The previous prime is 23215201. The next prime is 23215223. The reversal of 23215221 is 12251232.

It is not a de Polignac number, because 23215221 - 2⁵ = 23215189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 23215194 and 23215203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23215223) 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 7 ways as a sum of consecutive naturals, for example, 429885 + ... + 429938.

It is an arithmetic number, because the mean of its divisors is an integer number (4299120).

Almost surely, 2^23215221 is an apocalyptic number.

It is an amenable number.

23215221 is a deficient number, since it is larger than the sum of its proper divisors (11177739).

23215221 is an equidigital number, since it uses as much as digits as its factorization.

23215221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 859832 (or 859826 counting only the distinct ones).

The product of its digits is 240, while the sum is 18.

The square root of 23215221 is about 4818.2176165051. The cubic root of 23215221 is about 285.2709887893.

Adding to 23215221 its reverse (12251232), we get a palindrome (35466453).

It can be divided in two parts, 23215 and 221, that added together give a triangular number (23436 = T₂₁₆).

The spelling of 23215221 in words is "twenty-three million, two hundred fifteen thousand, two hundred twenty-one".