78138 has 16 divisors (see below), whose sum is σ = 173760. Its totient is φ = 26028.

The previous prime is 78137. The next prime is 78139. The reversal of 78138 is 83187.

It is an interprime number because it is at equal distance from previous prime (78137) and next prime (78139).

It is a super-2 number, since 2×78138² = 12211094088, which contains 22 as substring.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

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

It is not an unprimeable number, because it can be changed into a prime (78137) 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, 670 + ... + 777.

It is an arithmetic number, because the mean of its divisors is an integer number (10860).

2⁷⁸¹³⁸ is an apocalyptic number.

78138 is an abundant number, since it is smaller than the sum of its proper divisors (95622).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86880).

78138 is a wasteful number, since it uses less digits than its factorization.

78138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1458 (or 1452 counting only the distinct ones).

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

The square root of 78138 is about 279.5317513271. The cubic root of 78138 is about 42.7517697021.

It can be divided in two parts, 78 and 138, that added together give a cube (216 = 6³).

The spelling of 78138 in words is "seventy-eight thousand, one hundred thirty-eight".