78015 has 16 divisors (see below), whose sum is σ = 142848. Its totient is φ = 35616.

The previous prime is 78007. The next prime is 78017. The reversal of 78015 is 51087.

It is a happy number.

78015 is nontrivially palindromic in base 12.

It is not a de Polignac number, because 78015 - 2³ = 78007 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

78015 is a lucky number.

It is a nialpdrome in base 7.

It is a junction number, because it is equal to n+sod(n) for n = 77982 and 78000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78017) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 267 + ... + 476.

It is an arithmetic number, because the mean of its divisors is an integer number (8928).

2⁷⁸⁰¹⁵ is an apocalyptic number.

78015 is a deficient number, since it is larger than the sum of its proper divisors (64833).

78015 is a wasteful number, since it uses less digits than its factorization.

78015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758.

The product of its (nonzero) digits is 280, while the sum is 21.

The square root of 78015 is about 279.3116538922. The cubic root of 78015 is about 42.7293255252.

The spelling of 78015 in words is "seventy-eight thousand, fifteen".