1221100220120 has 32 divisors (see below), whose sum is σ = 2997245995920. Its totient is φ = 444036443520.

The previous prime is 1221100220113. The next prime is 1221100220167. The reversal of 1221100220120 is 210220011221.

It is a super-2 number, since 2×1221100220120² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221100220095 and 1221100220104.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1387613447 + ... + 1387614326.

Almost surely, 2^{1221100220120} is an apocalyptic number.

1221100220120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221100220120 is an abundant number, since it is smaller than the sum of its proper divisors (1776145775800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221100220120 is a wasteful number, since it uses less digits than its factorization.

1221100220120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2775227795 (or 2775227791 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 1221100220120 its reverse (210220011221), we get a palindrome (1431320231341).

The spelling of 1221100220120 in words is "one trillion, two hundred twenty-one billion, one hundred million, two hundred twenty thousand, one hundred twenty".