1331904 has 56 divisors (see below), whose sum is σ = 4031488. Its totient is φ = 380160.

The previous prime is 1331857. The next prime is 1331921. The reversal of 1331904 is 4091331.

It is a tau number, because it is divible by the number of its divisors (56).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 849 + ... + 1839.

2^1331904 is an apocalyptic number.

1331904 is a gapful number since it is divisible by the number (14) 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 1331904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2015744).

1331904 is an abundant number, since it is smaller than the sum of its proper divisors (2699584).

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

1331904 is an equidigital number, since it uses as much as digits as its factorization.

1331904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1013 (or 1003 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 1331904 is about 1154.0814529313. The cubic root of 1331904 is about 110.0248979453.

The spelling of 1331904 in words is "one million, three hundred thirty-one thousand, nine hundred four".