1211221220120 has 64 divisors (see below), whose sum is σ = 2735530475040. Its totient is φ = 482661273600.

The previous prime is 1211221220107. The next prime is 1211221220129. The reversal of 1211221220120 is 210221221121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211221220129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59770790 + ... + 59791050.

Almost surely, 2^{1211221220120} is an apocalyptic number.

1211221220120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211221220120 is an abundant number, since it is smaller than the sum of its proper divisors (1524309254920).

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

1211221220120 is a wasteful number, since it uses less digits than its factorization.

1211221220120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25836 (or 25832 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1211221220120 its reverse (210221221121), we get a palindrome (1421442441241).

It can be divided in two parts, 1211221 and 220120, that added together give a palindrome (1431341).

The spelling of 1211221220120 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, two hundred twenty thousand, one hundred twenty".