1221102100000 has 72 divisors (see below), whose sum is σ = 3004863871716. Its totient is φ = 488440800000.

The previous prime is 1221102099979. The next prime is 1221102100063. The reversal of 1221102100000 is 12011221.

It can be written as a sum of positive squares in 6 ways, for example, as 426215733904 + 794886366096 = 652852^2 + 891564^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a self number, because there is not a number n which added to its sum of digits gives 1221102100000.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6005511 + ... + 6205510.

Almost surely, 2^{1221102100000} is an apocalyptic number.

1221102100000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221102100000 is an abundant number, since it is smaller than the sum of its proper divisors (1783761771716).

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

1221102100000 is an frugal number, since it uses more digits than its factorization.

1221102100000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12211056 (or 12211028 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 1221102100000 its reverse (12011221), we get a palindrome (1221114111221).

The spelling of 1221102100000 in words is "one trillion, two hundred twenty-one billion, one hundred two million, one hundred thousand".