1220111212021 has 4 divisors (see below), whose sum is σ = 1313965920652. Its totient is φ = 1126256503392.

The previous prime is 1220111211989. The next prime is 1220111212051. The reversal of 1220111212021 is 1202121110221.

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 181892867121 + 1038218344900 = 426489^2 + 1018930^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220111212021 - 2⁵ = 1220111211989 is a prime.

It is a super-2 number, since 2×1220111212021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220111211986 and 1220111212004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220111212051) 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, 46927354296 + ... + 46927354321.

It is an arithmetic number, because the mean of its divisors is an integer number (328491480163).

Almost surely, 2^{1220111212021} is an apocalyptic number.

It is an amenable number.

1220111212021 is a deficient number, since it is larger than the sum of its proper divisors (93854708631).

1220111212021 is an equidigital number, since it uses as much as digits as its factorization.

1220111212021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93854708630.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1220111212021 its reverse (1202121110221), we get a palindrome (2422232322242).

The spelling of 1220111212021 in words is "one trillion, two hundred twenty billion, one hundred eleven million, two hundred twelve thousand, twenty-one".