1221211100120 has 48 divisors (see below), whose sum is σ = 3020226637680. Its totient is φ = 444076761920.

The previous prime is 1221211100117. The next prime is 1221211100143. The reversal of 1221211100120 is 210011121221.

It is a junction number, because it is equal to n+sod(n) for n = 1221211100095 and 1221211100104.

It is a congruent number.

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, 126153332 + ... + 126163011.

It is an arithmetic number, because the mean of its divisors is an integer number (62921388285).

Almost surely, 2^{1221211100120} is an apocalyptic number.

1221211100120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221211100120 is an abundant number, since it is smaller than the sum of its proper divisors (1799015537560).

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

1221211100120 is a wasteful number, since it uses less digits than its factorization.

1221211100120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252316376 (or 252316361 counting only the distinct ones).

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

Adding to 1221211100120 its reverse (210011121221), we get a palindrome (1431222221341).

The spelling of 1221211100120 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, one hundred thousand, one hundred twenty".