78813 has 20 divisors (see below), whose sum is σ = 135520. Its totient is φ = 44712.

The previous prime is 78809. The next prime is 78823. The reversal of 78813 is 31887.

It is not a de Polignac number, because 78813 - 2² = 78809 is a prime.

It is a super-2 number, since 2×78813² = 12422977938, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78803) 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 19 ways as a sum of consecutive naturals, for example, 498 + ... + 636.

It is an arithmetic number, because the mean of its divisors is an integer number (6776).

2⁷⁸⁸¹³ is an apocalyptic number.

It is an amenable number.

78813 is a deficient number, since it is larger than the sum of its proper divisors (56707).

78813 is a wasteful number, since it uses less digits than its factorization.

78813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158 (or 149 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 78813 is about 280.7365312887. The cubic root of 78813 is about 42.8745215234.

The spelling of 78813 in words is "seventy-eight thousand, eight hundred thirteen".