23212221 has 16 divisors (see below), whose sum is σ = 32420736. Its totient is φ = 14744576.

The previous prime is 23212207. The next prime is 23212247. The reversal of 23212221 is 12221232.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 23212221 - 2⁹ = 23211709 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 23212221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23212271) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23881 + ... + 24833.

It is an arithmetic number, because the mean of its divisors is an integer number (2026296).

Almost surely, 2^23212221 is an apocalyptic number.

It is an amenable number.

23212221 is a deficient number, since it is larger than the sum of its proper divisors (9208515).

23212221 is a wasteful number, since it uses less digits than its factorization.

23212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1332.

The product of its digits is 96, while the sum is 15.

The square root of 23212221 is about 4817.9062880052. The cubic root of 23212221 is about 285.2587001586.

Adding to 23212221 its reverse (12221232), we get a palindrome (35433453).

The spelling of 23212221 in words is "twenty-three million, two hundred twelve thousand, two hundred twenty-one".