78155 has 24 divisors (see below), whose sum is σ = 123120. Its totient is φ = 47040.

The previous prime is 78139. The next prime is 78157. The reversal of 78155 is 55187.

It is not a de Polignac number, because 78155 - 2⁴ = 78139 is a prime.

It is a super-2 number, since 2×78155² = 12216408050, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 78155.

It is not an unprimeable number, because it can be changed into a prime (78157) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2681 + ... + 2709.

It is an arithmetic number, because the mean of its divisors is an integer number (5130).

2⁷⁸¹⁵⁵ is an apocalyptic number.

78155 is a deficient number, since it is larger than the sum of its proper divisors (44965).

78155 is a wasteful number, since it uses less digits than its factorization.

78155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59 (or 52 counting only the distinct ones).

The product of its digits is 1400, while the sum is 26.

The square root of 78155 is about 279.5621576680. The cubic root of 78155 is about 42.7548698897.

It can be divided in two parts, 78 and 155, that multiplied together give a triangular number (12090 = T₁₅₅).

The spelling of 78155 in words is "seventy-eight thousand, one hundred fifty-five".