1221312113120 has 192 divisors, whose sum is σ = 3247650443520. Its totient is φ = 430160793600.

The previous prime is 1221312113069. The next prime is 1221312113143. The reversal of 1221312113120 is 213112131221.

It is a super-2 number, since 2×1221312113120² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1221312113092 and 1221312113101.

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, 9969359 + ... + 10091121.

It is an arithmetic number, because the mean of its divisors is an integer number (16914846060).

Almost surely, 2^{1221312113120} is an apocalyptic number.

1221312113120 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 1221312113120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1623825221760).

1221312113120 is an abundant number, since it is smaller than the sum of its proper divisors (2026338330400).

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

1221312113120 is a wasteful number, since it uses less digits than its factorization.

1221312113120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121969 (or 121961 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 1221312113120 its reverse (213112131221), we get a palindrome (1434424244341).

The spelling of 1221312113120 in words is "one trillion, two hundred twenty-one billion, three hundred twelve million, one hundred thirteen thousand, one hundred twenty".