1221220222 has 4 divisors (see below), whose sum is σ = 1831830336. Its totient is φ = 610610110.

The previous prime is 1221220199. The next prime is 1221220229. The reversal of 1221220222 is 2220221221.

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

It is a junction number, because it is equal to n+sod(n) for n = 1221220196 and 1221220205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221220229) 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 as a sum of consecutive naturals, namely, 305305054 + ... + 305305057.

It is an arithmetic number, because the mean of its divisors is an integer number (457957584).

Almost surely, 2^1221220222 is an apocalyptic number.

1221220222 is a deficient number, since it is larger than the sum of its proper divisors (610610114).

1221220222 is an equidigital number, since it uses as much as digits as its factorization.

1221220222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610610113.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 1221220222 is about 34945.9614547947. The cubic root of 1221220222 is about 1068.8858528353.

Adding to 1221220222 its reverse (2220221221), we get a palindrome (3441441443).

Subtracting 1221220222 from its reverse (2220221221), we obtain a palindrome (999000999).

The spelling of 1221220222 in words is "one billion, two hundred twenty-one million, two hundred twenty thousand, two hundred twenty-two".