222000021 has 20 divisors (see below), whose sum is σ = 342331264. Its totient is φ = 143224200.

The previous prime is 222000019. The next prime is 222000043. The reversal of 222000021 is 120000222.

It is not a de Polignac number, because 222000021 - 2¹ = 222000019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 221999967 and 222000012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (222000061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 41695 + ... + 46716.

Almost surely, 2^222000021 is an apocalyptic number.

It is an amenable number.

222000021 is a deficient number, since it is larger than the sum of its proper divisors (120331243).

222000021 is an equidigital number, since it uses as much as digits as its factorization.

222000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88454 (or 88445 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 222000021 is about 14899.6651304652. The cubic root of 222000021 is about 605.5049137436.

Adding to 222000021 its reverse (120000222), we get a palindrome (342000243).

The spelling of 222000021 in words is "two hundred twenty-two million, twenty-one", and thus it is an aban number.