78966857 has 4 divisors (see below), whose sum is σ = 79160340. Its totient is φ = 78773376.

The previous prime is 78966841. The next prime is 78966893. The reversal of 78966857 is 75866987.

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 39075001 + 39891856 = 6251^2 + 6316^2 .

It is a cyclic number.

It is not a de Polignac number, because 78966857 - 2⁴ = 78966841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78966257) 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, 96128 + ... + 96945.

It is an arithmetic number, because the mean of its divisors is an integer number (19790085).

Almost surely, 2^78966857 is an apocalyptic number.

It is an amenable number.

78966857 is a deficient number, since it is larger than the sum of its proper divisors (193483).

78966857 is a wasteful number, since it uses less digits than its factorization.

78966857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193482.

The product of its digits is 5080320, while the sum is 56.

The square root of 78966857 is about 8886.3297823117. The cubic root of 78966857 is about 429.0240295312.

The spelling of 78966857 in words is "seventy-eight million, nine hundred sixty-six thousand, eight hundred fifty-seven".