121221210111220 has 96 divisors (see below), whose sum is σ = 267017397454080. Its totient is φ = 46138858275840.

The previous prime is 121221210111137. The next prime is 121221210111233. The reversal of 121221210111220 is 22111012122121.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 116415046 + ... + 117451714.

It is an arithmetic number, because the mean of its divisors is an integer number (2781431223480).

Almost surely, 2^{121221210111220} is an apocalyptic number.

121221210111220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121221210111220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133508698727040).

121221210111220 is an abundant number, since it is smaller than the sum of its proper divisors (145796187342860).

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

121221210111220 is a wasteful number, since it uses less digits than its factorization.

121221210111220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1038025 (or 1038023 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 121221210111220 its reverse (22111012122121), we get a palindrome (143332222233341).

The spelling of 121221210111220 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, two hundred ten million, one hundred eleven thousand, two hundred twenty".