1220120212221 has 6 divisors (see below), whose sum is σ = 1762395862110. Its totient is φ = 813413474808.

The previous prime is 1220120212211. The next prime is 1220120212229. The reversal of 1220120212221 is 1222120210221.

It is a happy number.

1220120212221 is a `hidden beast` number, since 1 + 220 + 12 + 0 + 212 + 221 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1219889324196 + 230888025 = 1104486^2 + 15195^2 .

It is not a de Polignac number, because 1220120212221 - 2¹⁴ = 1220120195837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1220120212194 and 1220120212203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220120212229) 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, 67784456226 + ... + 67784456243.

It is an arithmetic number, because the mean of its divisors is an integer number (293732643685).

Almost surely, 2^{1220120212221} is an apocalyptic number.

It is an amenable number.

1220120212221 is a deficient number, since it is larger than the sum of its proper divisors (542275649889).

1220120212221 is a wasteful number, since it uses less digits than its factorization.

1220120212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135568912475 (or 135568912472 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 1220120212221 its reverse (1222120210221), we get a palindrome (2442240422442).

It can be divided in two parts, 1220120 and 212221, that added together give a palindrome (1432341).

The spelling of 1220120212221 in words is "one trillion, two hundred twenty billion, one hundred twenty million, two hundred twelve thousand, two hundred twenty-one".