78765 has 16 divisors (see below), whose sum is σ = 129600. Its totient is φ = 40832.

The previous prime is 78737. The next prime is 78779. The reversal of 78765 is 56787.

78765 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is a cyclic number.

It is not a de Polignac number, because 78765 - 2⁸ = 78509 is a prime.

It is an alternating number because its digits alternate between odd and even.

78765 is a lucky number.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 841 + ... + 929.

It is an arithmetic number, because the mean of its divisors is an integer number (8100).

2⁷⁸⁷⁶⁵ is an apocalyptic number.

It is an amenable number.

78765 is a deficient number, since it is larger than the sum of its proper divisors (50835).

78765 is a wasteful number, since it uses less digits than its factorization.

78765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156.

The product of its digits is 11760, while the sum is 33.

The square root of 78765 is about 280.6510288597. The cubic root of 78765 is about 42.8658157051.

Adding to 78765 its product of digits (11760), we get a triangular number (90525 = T₄₂₅).

The spelling of 78765 in words is "seventy-eight thousand, seven hundred sixty-five".