78381 has 8 divisors (see below), whose sum is σ = 116160. Its totient is φ = 52236.

The previous prime is 78367. The next prime is 78401. The reversal of 78381 is 18387.

It is not a de Polignac number, because 78381 - 2⁶ = 78317 is a prime.

It is a super-2 number, since 2×78381² = 12287162322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 2903 = 78381 / (7 + 8 + 3 + 8 + 1).

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1425 + ... + 1478.

It is an arithmetic number, because the mean of its divisors is an integer number (14520).

2⁷⁸³⁸¹ is an apocalyptic number.

It is an amenable number.

78381 is a deficient number, since it is larger than the sum of its proper divisors (37779).

78381 is a wasteful number, since it uses less digits than its factorization.

78381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2912 (or 2906 counting only the distinct ones).

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

The square root of 78381 is about 279.9660693727. The cubic root of 78381 is about 42.7960415007.

The spelling of 78381 in words is "seventy-eight thousand, three hundred eighty-one".