78804857 has 4 divisors (see below), whose sum is σ = 80934756. Its totient is φ = 76674960.

The previous prime is 78804839. The next prime is 78804871. The reversal of 78804857 is 75840887.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 47623801 + 31181056 = 6901^2 + 5584^2 .

It is a cyclic number.

It is not a de Polignac number, because 78804857 - 2¹⁴ = 78788473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78801857) 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, 1064894 + ... + 1064967.

It is an arithmetic number, because the mean of its divisors is an integer number (20233689).

Almost surely, 2^78804857 is an apocalyptic number.

It is an amenable number.

78804857 is a deficient number, since it is larger than the sum of its proper divisors (2129899).

78804857 is a wasteful number, since it uses less digits than its factorization.

78804857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2129898.

The product of its (nonzero) digits is 501760, while the sum is 47.

The square root of 78804857 is about 8877.2099783660. The cubic root of 78804857 is about 428.7304486660.

The spelling of 78804857 in words is "seventy-eight million, eight hundred four thousand, eight hundred fifty-seven".