1221011102220 has 192 divisors, whose sum is σ = 4321516932096. Its totient is φ = 250657182720.

The previous prime is 1221011102147. The next prime is 1221011102249. The reversal of 1221011102220 is 222011101221.

It is a super-2 number, since 2×1221011102220² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1221011102220.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2819986 + ... + 3224025.

It is an arithmetic number, because the mean of its divisors is an integer number (22507900688).

Almost surely, 2^{1221011102220} is an apocalyptic number.

1221011102220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221011102220 is an abundant number, since it is smaller than the sum of its proper divisors (3100505829876).

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

1221011102220 is a wasteful number, since it uses less digits than its factorization.

1221011102220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6044080 (or 6044078 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1221011102220 its reverse (222011101221), we get a palindrome (1443022203441).

Subtracting from 1221011102220 its reverse (222011101221), we obtain a palindrome (999000000999).

It can be divided in two parts, 1221011 and 102220, that added together give a palindrome (1323231).

The spelling of 1221011102220 in words is "one trillion, two hundred twenty-one billion, eleven million, one hundred two thousand, two hundred twenty".