513805 has 4 divisors (see below), whose sum is σ = 616572. Its totient is φ = 411040.

The previous prime is 513781. The next prime is 513829. The reversal of 513805 is 508315.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 508315 = 5 ⋅101663.

It is an interprime number because it is at equal distance from previous prime (513781) and next prime (513829).

It can be written as a sum of positive squares in 2 ways, for example, as 385641 + 128164 = 621^2 + 358^2 .

It is not a de Polignac number, because 513805 - 2¹¹ = 511757 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 513805.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51376 + ... + 51385.

It is an arithmetic number, because the mean of its divisors is an integer number (154143).

2⁵¹³⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

513805 is a deficient number, since it is larger than the sum of its proper divisors (102767).

513805 is a wasteful number, since it uses less digits than its factorization.

513805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102766.

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 513805 is about 716.8019252206. The cubic root of 513805 is about 80.0939001580.

The spelling of 513805 in words is "five hundred thirteen thousand, eight hundred five".