1220221002221 has 16 divisors (see below), whose sum is σ = 1391422258800. Its totient is φ = 1060071763968.

The previous prime is 1220221002211. The next prime is 1220221002233. The reversal of 1220221002221 is 1222001220221.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 38488946596 + 1181732055625 = 196186^2 + 1087075^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1220221002221 is a prime.

It is a super-2 number, since 2×1220221002221² (a number of 25 digits) contains 22 as substring.

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 1220221002221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220221002211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12239945 + ... + 12339233.

It is an arithmetic number, because the mean of its divisors is an integer number (86963891175).

Almost surely, 2^{1220221002221} is an apocalyptic number.

It is an amenable number.

1220221002221 is a deficient number, since it is larger than the sum of its proper divisors (171201256579).

1220221002221 is a wasteful number, since it uses less digits than its factorization.

1220221002221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154928.

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

Adding to 1220221002221 its reverse (1222001220221), we get a palindrome (2442222222442).

The spelling of 1220221002221 in words is "one trillion, two hundred twenty billion, two hundred twenty-one million, two thousand, two hundred twenty-one".