22428221 has 4 divisors (see below), whose sum is σ = 23151744. Its totient is φ = 21704700.

The previous prime is 22428209. The next prime is 22428233. The reversal of 22428221 is 12282422.

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.

It is an interprime number because it is at equal distance from previous prime (22428209) and next prime (22428233).

It is a cyclic number.

It is not a de Polignac number, because 22428221 - 2⁶ = 22428157 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 (22427221) 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, 361715 + ... + 361776.

It is an arithmetic number, because the mean of its divisors is an integer number (5787936).

Almost surely, 2^22428221 is an apocalyptic number.

It is an amenable number.

22428221 is a deficient number, since it is larger than the sum of its proper divisors (723523).

22428221 is an equidigital number, since it uses as much as digits as its factorization.

22428221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 723522.

The product of its digits is 1024, while the sum is 23.

The square root of 22428221 is about 4735.8442753114. The cubic root of 22428221 is about 282.0102816364.

The spelling of 22428221 in words is "twenty-two million, four hundred twenty-eight thousand, two hundred twenty-one".