22031221 has 4 divisors (see below), whose sum is σ = 22042944. Its totient is φ = 22019500.

The previous prime is 22031209. The next prime is 22031237. The reversal of 22031221 is 12213022.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12213022 = 2 ⋅6106511.

It is a cyclic number.

It is not a de Polignac number, because 22031221 - 2¹¹ = 22029173 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 (22031281) 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, 2335 + ... + 7036.

It is an arithmetic number, because the mean of its divisors is an integer number (5510736).

Almost surely, 2^22031221 is an apocalyptic number.

It is an amenable number.

22031221 is a deficient number, since it is larger than the sum of its proper divisors (11723).

22031221 is an equidigital number, since it uses as much as digits as its factorization.

22031221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11722.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 22031221 is about 4693.7427496615. The cubic root of 22031221 is about 280.3364196100.

Adding to 22031221 its reverse (12213022), we get a palindrome (34244243).

The spelling of 22031221 in words is "twenty-two million, thirty-one thousand, two hundred twenty-one".