1220222221 has 2 divisors, whose sum is σ = 1220222222. Its totient is φ = 1220222220.

The previous prime is 1220222219. The next prime is 1220222249. The reversal of 1220222221 is 1222220221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 840362121 + 379860100 = 28989^2 + 19490^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220222221 - 2¹ = 1220222219 is a prime.

Together with 1220222219, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 1220222195 and 1220222204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220222261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610111110 + 610111111.

It is an arithmetic number, because the mean of its divisors is an integer number (610111111).

Almost surely, 2^1220222221 is an apocalyptic number.

It is an amenable number.

1220222221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220222221 is an equidigital number, since it uses as much as digits as its factorization.

1220222221 is an odious number, because the sum of its binary digits is odd.

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

The square root of 1220222221 is about 34931.6793326631. The cubic root of 1220222221 is about 1068.5946031897.

Adding to 1220222221 its reverse (1222220221), we get a palindrome (2442442442).

The spelling of 1220222221 in words is "one billion, two hundred twenty million, two hundred twenty-two thousand, two hundred twenty-one".