1331640 has 96 divisors (see below), whose sum is σ = 4520880. Its totient is φ = 352512.

The previous prime is 1331633. The next prime is 1331641. The reversal of 1331640 is 461331.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1331641) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9652 + ... + 9788.

2^1331640 is an apocalyptic number.

1331640 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 1331640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2260440).

1331640 is an abundant number, since it is smaller than the sum of its proper divisors (3189240).

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

1331640 is a wasteful number, since it uses less digits than its factorization.

1331640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163 (or 147 counting only the distinct ones).

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

The square root of 1331640 is about 1153.9670705874. The cubic root of 1331640 is about 110.0176280289.

Adding to 1331640 its reverse (461331), we get a palindrome (1792971).

The spelling of 1331640 in words is "one million, three hundred thirty-one thousand, six hundred forty".