1221233211320 has 64 divisors (see below), whose sum is σ = 2837769984000. Its totient is φ = 472509210240.

The previous prime is 1221233211307. The next prime is 1221233211371. The reversal of 1221233211320 is 231123321221.

It is a super-2 number, since 2×1221233211320² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2368157 + ... + 2837363.

It is an arithmetic number, because the mean of its divisors is an integer number (44340156000).

Almost surely, 2^{1221233211320} is an apocalyptic number.

1221233211320 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 1221233211320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1418884992000).

1221233211320 is an abundant number, since it is smaller than the sum of its proper divisors (1616536772680).

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

1221233211320 is a wasteful number, since it uses less digits than its factorization.

1221233211320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471348 (or 471344 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 1221233211320 its reverse (231123321221), we get a palindrome (1452356532541).

The spelling of 1221233211320 in words is "one trillion, two hundred twenty-one billion, two hundred thirty-three million, two hundred eleven thousand, three hundred twenty".