1220120202121 has 4 divisors (see below), whose sum is σ = 1220124935700. Its totient is φ = 1220115468544.

The previous prime is 1220120202031. The next prime is 1220120202139. The reversal of 1220120202121 is 1212020210221.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 66429392121 + 1153690810000 = 257739^2 + 1074100^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220120202121 - 2²¹ = 1220118104969 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220120202095 and 1220120202104.

It is not an unprimeable number, because it can be changed into a prime (1220120202181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1956436 + ... + 2503573.

It is an arithmetic number, because the mean of its divisors is an integer number (305031233925).

Almost surely, 2^{1220120202121} is an apocalyptic number.

It is an amenable number.

1220120202121 is a deficient number, since it is larger than the sum of its proper divisors (4733579).

1220120202121 is an equidigital number, since it uses as much as digits as its factorization.

1220120202121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4733578.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1220120202121 its reverse (1212020210221), we get a palindrome (2432140412342).

It can be divided in two parts, 1220120 and 202121, that added together give a palindrome (1422241).

The spelling of 1220120202121 in words is "one trillion, two hundred twenty billion, one hundred twenty million, two hundred two thousand, one hundred twenty-one".