78931 has 4 divisors (see below), whose sum is σ = 83592. Its totient is φ = 74272.

The previous prime is 78929. The next prime is 78941. The reversal of 78931 is 13987.

78931 is an esthetic number in base 8, because in such base its adjacent digits differ by 1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13987 = 71 ⋅197.

It is a cyclic number.

It is not a de Polignac number, because 78931 - 2¹ = 78929 is a prime.

It is a super-2 number, since 2×78931² = 12460205522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78931.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2305 + ... + 2338.

It is an arithmetic number, because the mean of its divisors is an integer number (20898).

2⁷⁸⁹³¹ is an apocalyptic number.

78931 is a deficient number, since it is larger than the sum of its proper divisors (4661).

78931 is a wasteful number, since it uses less digits than its factorization.

It is an anagram of its base 12 representation: 78931 = (39817)₁₂.

78931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4660.

The product of its digits is 1512, while the sum is 28.

The square root of 78931 is about 280.9466141458. The cubic root of 78931 is about 42.8959083113.

It can be divided in two parts, 789 and 31, that added together give a triangular number (820 = T₄₀).

The spelling of 78931 in words is "seventy-eight thousand, nine hundred thirty-one".