1221121011020 has 12 divisors (see below), whose sum is σ = 2564354123184. Its totient is φ = 488448404400.

The previous prime is 1221121010981. The next prime is 1221121011049. The reversal of 1221121011020 is 201101211221.

It is a super-2 number, since 2×1221121011020² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221121010986 and 1221121011004.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30528025256 + ... + 30528025295.

It is an arithmetic number, because the mean of its divisors is an integer number (213696176932).

Almost surely, 2^{1221121011020} is an apocalyptic number.

1221121011020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221121011020 is an abundant number, since it is smaller than the sum of its proper divisors (1343233112164).

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

1221121011020 is a wasteful number, since it uses less digits than its factorization.

1221121011020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61056050560 (or 61056050558 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1221121011020 its reverse (201101211221), we get a palindrome (1422222222241).

The spelling of 1221121011020 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-one million, eleven thousand, twenty".