813005 has 4 divisors (see below), whose sum is σ = 975612.
Its totient is φ = 650400.
The previous prime is 812969. The next prime is 813013. The reversal of 813005 is 500318.
It is a semiprime because it is the product of two primes.
It can be written as a sum of positive squares in 2 ways, for example, as 561001 + 252004 = 749^2 + 502^2
It is not a de Polignac number, because 813005 - 210 = 811981 is a prime.
It is a Duffinian number.
It is a congruent number.
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, 81296 + ... + 81305.
It is an arithmetic number, because the mean of its divisors is an integer number (243903).
2813005 is an apocalyptic number.
It is an amenable number.
813005 is a deficient number, since it is larger than the sum of its proper divisors (162607).
813005 is a wasteful number, since it uses less digits than its factorization.
813005 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 162606.
The product of its (nonzero) digits is 120, while the sum is 17.
The square root of 813005 is about 901.6678989517.
The cubic root of 813005 is about 93.3321074102.
The spelling of 813005 in words is "eight hundred thirteen thousand, five".