78145 has 4 divisors (see below), whose sum is σ = 93780. Its totient is φ = 62512.
The previous prime is 78139. The next prime is 78157. The reversal of 78145 is 54187.
It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54187 = 7 ⋅7741.
It can be written as a sum of positive squares in 2 ways, for example, as 61504 + 16641 = 248^2 + 129^2 .
It is a cyclic number.
It is not a de Polignac number, because 78145 - 23 = 78137 is a prime.
It is a super-2 number, since 2×781452 = 12213282050, which contains 22 as substring.
It is a d-powerful number, because it can be written as 7 + 8 + 1 + 4 + 57 .
It is an alternating number because its digits alternate between odd and even.
78145 is a lucky number.
It is a congruent number.
It is an unprimeable number.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7810 + ... + 7819.
It is an arithmetic number, because the mean of its divisors is an integer number (23445).
278145 is an apocalyptic number.
It is an amenable number.
78145 is a deficient number, since it is larger than the sum of its proper divisors (15635).
78145 is a wasteful number, since it uses less digits than its factorization.
78145 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 15634.
The product of its digits is 1120, while the sum is 25.
The square root of 78145 is about 279.5442719857. The cubic root of 78145 is about 42.7530463044.
The spelling of 78145 in words is "seventy-eight thousand, one hundred forty-five".
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