1221002011100 has 18 divisors (see below), whose sum is σ = 2649574364304. Its totient is φ = 488400804400.

The previous prime is 1221002011093. The next prime is 1221002011111. The reversal of 1221002011100 is 11102001221.

It is a super-2 number, since 2×1221002011100² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6105009956 + ... + 6105010155.

Almost surely, 2^{1221002011100} is an apocalyptic number.

1221002011100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221002011100 is an abundant number, since it is smaller than the sum of its proper divisors (1428572353204).

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

1221002011100 is a wasteful number, since it uses less digits than its factorization.

1221002011100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12210020125 (or 12210020118 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 1221002011100 its reverse (11102001221), we get a palindrome (1232104012321).

The spelling of 1221002011100 in words is "one trillion, two hundred twenty-one billion, two million, eleven thousand, one hundred".