78865823 has 4 divisors (see below), whose sum is σ = 78952560. Its totient is φ = 78779088.

The previous prime is 78865817. The next prime is 78865883. The reversal of 78865823 is 32856887.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78865823 - 2¹⁴ = 78849439 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78865883) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41990 + ... + 43827.

It is an arithmetic number, because the mean of its divisors is an integer number (19738140).

Almost surely, 2^78865823 is an apocalyptic number.

78865823 is a deficient number, since it is larger than the sum of its proper divisors (86737).

78865823 is an equidigital number, since it uses as much as digits as its factorization.

78865823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86736.

The product of its digits is 645120, while the sum is 47.

The square root of 78865823 is about 8880.6431636453. The cubic root of 78865823 is about 428.8409801063.

The spelling of 78865823 in words is "seventy-eight million, eight hundred sixty-five thousand, eight hundred twenty-three".