78861 has 8 divisors (see below), whose sum is σ = 106624. Its totient is φ = 51840.

The previous prime is 78857. The next prime is 78877. The reversal of 78861 is 16887.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78861 - 2² = 78857 is a prime.

It is a Duffinian number.

78861 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156 + ... + 426.

It is an arithmetic number, because the mean of its divisors is an integer number (13328).

2⁷⁸⁸⁶¹ is an apocalyptic number.

It is an amenable number.

78861 is a deficient number, since it is larger than the sum of its proper divisors (27763).

78861 is a wasteful number, since it uses less digits than its factorization.

78861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371.

The product of its digits is 2688, while the sum is 30.

The square root of 78861 is about 280.8220076846. The cubic root of 78861 is about 42.8832238076.

It can be divided in two parts, 7886 and 1, that added together give a palindrome (7887).

The spelling of 78861 in words is "seventy-eight thousand, eight hundred sixty-one".