1291885 has 12 divisors (see below), whose sum is σ = 1803708. Its totient is φ = 885696.

The previous prime is 1291883. The next prime is 1291907. The reversal of 1291885 is 5881921.

It can be written as a sum of positive squares in 2 ways, for example, as 550564 + 741321 = 742^2 + 861^2 .

It is not a de Polignac number, because 1291885 - 2¹ = 1291883 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1291885.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2392 + ... + 2881.

It is an arithmetic number, because the mean of its divisors is an integer number (150309).

2^1291885 is an apocalyptic number.

It is an amenable number.

1291885 is a deficient number, since it is larger than the sum of its proper divisors (511823).

1291885 is an equidigital number, since it uses as much as digits as its factorization.

1291885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5292 (or 5285 counting only the distinct ones).

The product of its digits is 5760, while the sum is 34.

The square root of 1291885 is about 1136.6111912171. The cubic root of 1291885 is about 108.9117204580.

The spelling of 1291885 in words is "one million, two hundred ninety-one thousand, eight hundred eighty-five".