1291604 has 6 divisors (see below), whose sum is σ = 2260314. Its totient is φ = 645800.

The previous prime is 1291603. The next prime is 1291637. The reversal of 1291604 is 4061921.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1106704 + 184900 = 1052^2 + 430^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1291604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161447 + ... + 161454.

It is an arithmetic number, because the mean of its divisors is an integer number (376719).

2^1291604 is an apocalyptic number.

It is an amenable number.

1291604 is a deficient number, since it is larger than the sum of its proper divisors (968710).

1291604 is a wasteful number, since it uses less digits than its factorization.

1291604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322905 (or 322903 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 1291604 is about 1136.4875714235. The cubic root of 1291604 is about 108.9038233638.

The spelling of 1291604 in words is "one million, two hundred ninety-one thousand, six hundred four".