905813 has 4 divisors (see below), whose sum is σ = 927948. Its totient is φ = 883680.

The previous prime is 905803. The next prime is 905819. The reversal of 905813 is 318509.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 318509 = 431 ⋅739.

It can be written as a sum of positive squares in 2 ways, for example, as 418609 + 487204 = 647^2 + 698^2 .

It is a cyclic number.

It is not a de Polignac number, because 905813 - 2¹⁰ = 904789 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (905819) 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 in 3 ways as a sum of consecutive naturals, for example, 11006 + ... + 11087.

It is an arithmetic number, because the mean of its divisors is an integer number (231987).

2⁹⁰⁵⁸¹³ is an apocalyptic number.

It is an amenable number.

905813 is a deficient number, since it is larger than the sum of its proper divisors (22135).

905813 is a wasteful number, since it uses less digits than its factorization.

905813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22134.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 905813 is about 951.7420869122. The cubic root of 905813 is about 96.7563588197.

The spelling of 905813 in words is "nine hundred five thousand, eight hundred thirteen".