1331720 has 48 divisors (see below), whose sum is σ = 3261060. Its totient is φ = 489216.

The previous prime is 1331719. The next prime is 1331749. The reversal of 1331720 is 271331.

It can be written as a sum of positive squares in 6 ways, for example, as 481636 + 850084 = 694^2 + 922^2 .

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, 6662 + ... + 6858.

2^1331720 is an apocalyptic number.

1331720 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 1331720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1630530).

1331720 is an abundant number, since it is smaller than the sum of its proper divisors (1929340).

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

1331720 is a wasteful number, since it uses less digits than its factorization.

1331720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234 (or 217 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 17.

The square root of 1331720 is about 1154.0017331010. The cubic root of 1331720 is about 110.0198311353.

The spelling of 1331720 in words is "one million, three hundred thirty-one thousand, seven hundred twenty".