222212021 has 4 divisors (see below), whose sum is σ = 222293292. Its totient is φ = 222130752.

The previous prime is 222212009. The next prime is 222212063. The reversal of 222212021 is 120212222.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 65836996 + 156375025 = 8114^2 + 12505^2 .

It is a cyclic number.

It is not a de Polignac number, because 222212021 - 2²² = 218017717 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 222211987 and 222212005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (222242021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36386 + ... + 42051.

It is an arithmetic number, because the mean of its divisors is an integer number (55573323).

Almost surely, 2^222212021 is an apocalyptic number.

It is an amenable number.

222212021 is a deficient number, since it is larger than the sum of its proper divisors (81271).

222212021 is an equidigital number, since it uses as much as digits as its factorization.

222212021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81270.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 222212021 is about 14906.7776866766. Note that the first 3 decimals coincide. The cubic root of 222212021 is about 605.6975957101.

Adding to 222212021 its reverse (120212222), we get a palindrome (342424243).

It can be divided in two parts, 22221 and 2021, that added together give a palindrome (24242).

The spelling of 222212021 in words is "two hundred twenty-two million, two hundred twelve thousand, twenty-one".