1205891 has 2 divisors, whose sum is σ = 1205892. Its totient is φ = 1205890.

The previous prime is 1205843. The next prime is 1205899. The reversal of 1205891 is 1985021.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1205891 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1205891.

It is not a weakly prime, because it can be changed into another prime (1205899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 602945 + 602946.

It is an arithmetic number, because the mean of its divisors is an integer number (602946).

2^1205891 is an apocalyptic number.

1205891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1205891 is an equidigital number, since it uses as much as digits as its factorization.

1205891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 1205891 is about 1098.1306843905. The cubic root of 1205891 is about 106.4394654040.

The spelling of 1205891 in words is "one million, two hundred five thousand, eight hundred ninety-one".