78666 has 16 divisors (see below), whose sum is σ = 179904. Its totient is φ = 22464.

The previous prime is 78653. The next prime is 78691. The reversal of 78666 is 66687.

78666 is a modest number, since divided by 666 gives 78 as remainder.

It is a plaindrome in base 16.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 895 + ... + 978.

It is an arithmetic number, because the mean of its divisors is an integer number (11244).

2⁷⁸⁶⁶⁶ is an apocalyptic number.

78666 is an abundant number, since it is smaller than the sum of its proper divisors (101238).

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 (89952).

78666 is a wasteful number, since it uses less digits than its factorization.

78666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1885.

The product of its digits is 12096, while the sum is 33.

The square root of 78666 is about 280.4745977803. The cubic root of 78666 is about 42.8478487783.

The spelling of 78666 in words is "seventy-eight thousand, six hundred sixty-six".