1220112212221 has 6 divisors (see below), whose sum is σ = 1419314206110. Its totient is φ = 1045810467576.

The previous prime is 1220112212213. The next prime is 1220112212227. The reversal of 1220112212221 is 1222122110221.

It can be written as a sum of positive squares in only one way, i.e., 1177680744100 + 42431468121 = 1085210^2 + 205989^2 .

It is not a de Polignac number, because 1220112212221 - 2³ = 1220112212213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220112212227) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12450124566 + ... + 12450124663.

It is an arithmetic number, because the mean of its divisors is an integer number (236552367685).

Almost surely, 2^{1220112212221} is an apocalyptic number.

It is an amenable number.

1220112212221 is a deficient number, since it is larger than the sum of its proper divisors (199201993889).

1220112212221 is an equidigital number, since it uses as much as digits as its factorization.

1220112212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24900249243 (or 24900249236 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 1220112212221 its reverse (1222122110221), we get a palindrome (2442234322442).

The spelling of 1220112212221 in words is "one trillion, two hundred twenty billion, one hundred twelve million, two hundred twelve thousand, two hundred twenty-one".