78811 has 4 divisors (see below), whose sum is σ = 80352. Its totient is φ = 77272.

The previous prime is 78809. The next prime is 78823. The reversal of 78811 is 11887.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78811 - 2¹ = 78809 is a prime.

It is a super-2 number, since 2×78811² = 12422347442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78311) 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, 691 + ... + 796.

It is an arithmetic number, because the mean of its divisors is an integer number (20088).

2⁷⁸⁸¹¹ is an apocalyptic number.

78811 is a deficient number, since it is larger than the sum of its proper divisors (1541).

78811 is a wasteful number, since it uses less digits than its factorization.

78811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1540.

The product of its digits is 448, while the sum is 25.

The square root of 78811 is about 280.7329692074. The cubic root of 78811 is about 42.8741588515.

It can be divided in two parts, 788 and 11, that multiplied together give a palindrome (8668).

The spelling of 78811 in words is "seventy-eight thousand, eight hundred eleven".