1321331988 has 48 divisors (see below), whose sum is σ = 3201770880. Its totient is φ = 423609984.

The previous prime is 1321331981. The next prime is 1321332013. The reversal of 1321331988 is 8891331231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321331981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 84306 + ... + 98742.

It is an arithmetic number, because the mean of its divisors is an integer number (66703560).

Almost surely, 2^1321331988 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 1321331988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1600885440).

1321331988 is an abundant number, since it is smaller than the sum of its proper divisors (1880438892).

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

1321331988 is a wasteful number, since it uses less digits than its factorization.

1321331988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14736 (or 14734 counting only the distinct ones).

The product of its digits is 31104, while the sum is 39.

The square root of 1321331988 is about 36350.1305087066. The cubic root of 1321331988 is about 1097.3301610188.

The spelling of 1321331988 in words is "one billion, three hundred twenty-one million, three hundred thirty-one thousand, nine hundred eighty-eight".