813855 has 32 divisors (see below), whose sum is σ = 1557504. Its totient is φ = 354816.

The previous prime is 813847. The next prime is 813863. The reversal of 813855 is 558318.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (813847) and next prime (813863).

It is not a de Polignac number, because 813855 - 2³ = 813847 is a prime.

It is a super-2 number, since 2×813855² = 1324719922050, which contains 22 as substring.

813855 is a lucky 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 813855.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2247 + ... + 2583.

It is an arithmetic number, because the mean of its divisors is an integer number (48672).

2⁸¹³⁸⁵⁵ is an apocalyptic number.

813855 is a deficient number, since it is larger than the sum of its proper divisors (743649).

813855 is a wasteful number, since it uses less digits than its factorization.

813855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375.

The product of its digits is 4800, while the sum is 30.

The square root of 813855 is about 902.1391245257. The cubic root of 813855 is about 93.3646224460.

The spelling of 813855 in words is "eight hundred thirteen thousand, eight hundred fifty-five".