1221012021120 has 64 divisors (see below), whose sum is σ = 3891975823440. Its totient is φ = 325603205120.

The previous prime is 1221012021109. The next prime is 1221012021149. The reversal of 1221012021120 is 211202101221.

It is a tau number, because it is divible by the number of its divisors (64).

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 1221012021120.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 317969961 + ... + 317973800.

Almost surely, 2^{1221012021120} is an apocalyptic number.

1221012021120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221012021120 is an abundant number, since it is smaller than the sum of its proper divisors (2670963802320).

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

1221012021120 is an equidigital number, since it uses as much as digits as its factorization.

1221012021120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 635943783 (or 635943771 counting only the distinct ones).

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

Adding to 1221012021120 its reverse (211202101221), we get a palindrome (1432214122341).

The spelling of 1221012021120 in words is "one trillion, two hundred twenty-one billion, twelve million, twenty-one thousand, one hundred twenty".