1323131220 has 192 divisors, whose sum is σ = 4252227840. Its totient is φ = 341392896.

The previous prime is 1323131207. The next prime is 1323131237. The reversal of 1323131220 is 221313231.

1323131220 is a `hidden beast` number, since 132 + 313 + 1 + 220 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1323131193 and 1323131202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2375182 + ... + 2375738.

It is an arithmetic number, because the mean of its divisors is an integer number (22147020).

Almost surely, 2^1323131220 is an apocalyptic number.

1323131220 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 1323131220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2126113920).

1323131220 is an abundant number, since it is smaller than the sum of its proper divisors (2929096620).

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

1323131220 is a wasteful number, since it uses less digits than its factorization.

1323131220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 711 (or 703 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 1323131220 is about 36374.8707214198. The cubic root of 1323131220 is about 1097.8280061453.

Adding to 1323131220 its reverse (221313231), we get a palindrome (1544444451).

The spelling of 1323131220 in words is "one billion, three hundred twenty-three million, one hundred thirty-one thousand, two hundred twenty".