1291863 has 16 divisors (see below), whose sum is σ = 1843200. Its totient is φ = 803040.

The previous prime is 1291861. The next prime is 1291877. The reversal of 1291863 is 3681921.

It is not a de Polignac number, because 1291863 - 2¹ = 1291861 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1291863.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291861) 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 15 ways as a sum of consecutive naturals, for example, 2458 + ... + 2936.

It is an arithmetic number, because the mean of its divisors is an integer number (115200).

2^1291863 is an apocalyptic number.

1291863 is a deficient number, since it is larger than the sum of its proper divisors (551337).

1291863 is a wasteful number, since it uses less digits than its factorization.

1291863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 542.

The product of its digits is 2592, while the sum is 30.

The square root of 1291863 is about 1136.6015132842. The cubic root of 1291863 is about 108.9111022215.

The spelling of 1291863 in words is "one million, two hundred ninety-one thousand, eight hundred sixty-three".