1266805 has 4 divisors (see below), whose sum is σ = 1520172. Its totient is φ = 1013440.

The previous prime is 1266799. The next prime is 1266841. The reversal of 1266805 is 5086621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5086621 = 17 ⋅299213.

It can be written as a sum of positive squares in 2 ways, for example, as 362404 + 904401 = 602^2 + 951^2 .

It is not a de Polignac number, because 1266805 - 2⁷ = 1266677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 126676 + ... + 126685.

It is an arithmetic number, because the mean of its divisors is an integer number (380043).

2^1266805 is an apocalyptic number.

It is an amenable number.

1266805 is a deficient number, since it is larger than the sum of its proper divisors (253367).

1266805 is an equidigital number, since it uses as much as digits as its factorization.

1266805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253366.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 1266805 is about 1125.5243222605. The cubic root of 1266805 is about 108.2023242098.

The spelling of 1266805 in words is "one million, two hundred sixty-six thousand, eight hundred five".