22221999 has 24 divisors (see below), whose sum is σ = 33668880. Its totient is φ = 14485536.

The previous prime is 22221977. The next prime is 22222049. The reversal of 22221999 is 99912222.

It is not a de Polignac number, because 22221999 - 2⁹ = 22221487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22221949) 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 23 ways as a sum of consecutive naturals, for example, 75697 + ... + 75989.

It is an arithmetic number, because the mean of its divisors is an integer number (1402870).

Almost surely, 2^22221999 is an apocalyptic number.

22221999 is a deficient number, since it is larger than the sum of its proper divisors (11446881).

22221999 is an equidigital number, since it uses as much as digits as its factorization.

22221999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408 (or 349 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 22221999 is about 4714.0215315588. The cubic root of 22221999 is about 281.1432803995.

It can be divided in two parts, 22221 and 999, that added together give a triangular number (23220 = T₂₁₅).

The spelling of 22221999 in words is "twenty-two million, two hundred twenty-one thousand, nine hundred ninety-nine".