1321331128 has 48 divisors (see below), whose sum is σ = 2719964520. Its totient is φ = 598206336.

The previous prime is 1321331111. The next prime is 1321331159. The reversal of 1321331128 is 8211331231.

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 11 ways as a sum of consecutive naturals, for example, 289875 + ... + 294397.

Almost surely, 2^1321331128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1321331128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1359982260).

1321331128 is an abundant number, since it is smaller than the sum of its proper divisors (1398633392).

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

1321331128 is a wasteful number, since it uses less digits than its factorization.

1321331128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4648 (or 4591 counting only the distinct ones).

The product of its digits is 864, while the sum is 25.

The square root of 1321331128 is about 36350.1186793111. The cubic root of 1321331128 is about 1097.3299229499.

Adding to 1321331128 its reverse (8211331231), we get a palindrome (9532662359).

The spelling of 1321331128 in words is "one billion, three hundred twenty-one million, three hundred thirty-one thousand, one hundred twenty-eight".