1220120022221 has 6 divisors (see below), whose sum is σ = 1296113657130. Its totient is φ = 1148348255936.

The previous prime is 1220120022161. The next prime is 1220120022239. The reversal of 1220120022221 is 1222200210221.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 704508422500 + 515611599721 = 839350^2 + 718061^2 .

It is not a de Polignac number, because 1220120022221 - 2¹⁸ = 1220119760077 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1220120022221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220120022271) 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 5 ways as a sum of consecutive naturals, for example, 2110934006 + ... + 2110934583.

It is an arithmetic number, because the mean of its divisors is an integer number (216018942855).

Almost surely, 2^{1220120022221} is an apocalyptic number.

It is an amenable number.

1220120022221 is a deficient number, since it is larger than the sum of its proper divisors (75993634909).

1220120022221 is an equidigital number, since it uses as much as digits as its factorization.

1220120022221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4221868623 (or 4221868606 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 1220120022221 its reverse (1222200210221), we get a palindrome (2442320232442).

The spelling of 1220120022221 in words is "one trillion, two hundred twenty billion, one hundred twenty million, twenty-two thousand, two hundred twenty-one".