78857 has 2 divisors, whose sum is σ = 78858. Its totient is φ = 78856.

The previous prime is 78853. The next prime is 78877. The reversal of 78857 is 75887.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59536 + 19321 = 244^2 + 139^2 .

It is a cyclic number.

It is not a de Polignac number, because 78857 - 2² = 78853 is a prime.

It is a zygodrome in base 3.

It is not a weakly prime, because it can be changed into another prime (78853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39428 + 39429.

It is an arithmetic number, because the mean of its divisors is an integer number (39429).

2⁷⁸⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

78857 is a deficient number, since it is larger than the sum of its proper divisors (1).

78857 is an equidigital number, since it uses as much as digits as its factorization.

78857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15680, while the sum is 35.

The square root of 78857 is about 280.8148856453. The cubic root of 78857 is about 42.8824987522.

The spelling of 78857 in words is "seventy-eight thousand, eight hundred fifty-seven".