1221311120 has 40 divisors (see below), whose sum is σ = 2842403640. Its totient is φ = 488033280.

The previous prime is 1221311111. The next prime is 1221311149. The reversal of 1221311120 is 211131221.

1221311120 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 8042896 + 1213268224 = 2836^2 + 34832^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 1221311095 and 1221311104.

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, 78380 + ... + 92660.

It is an arithmetic number, because the mean of its divisors is an integer number (71060091).

Almost surely, 2^1221311120 is an apocalyptic number.

1221311120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221311120 is an abundant number, since it is smaller than the sum of its proper divisors (1621092520).

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

1221311120 is a wasteful number, since it uses less digits than its factorization.

1221311120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15363 (or 15357 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 14.

The square root of 1221311120 is about 34947.2619814486. The cubic root of 1221311120 is about 1068.9123719877.

Adding to 1221311120 its reverse (211131221), we get a palindrome (1432442341).

The spelling of 1221311120 in words is "one billion, two hundred twenty-one million, three hundred eleven thousand, one hundred twenty".