857842 has 8 divisors (see below), whose sum is σ = 1291500. Its totient is φ = 427344.

The previous prime is 857839. The next prime is 857851. The reversal of 857842 is 248758.

It can be written as a sum of positive squares in 2 ways, for example, as 690561 + 167281 = 831^2 + 409^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 857798 and 857807.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84 + ... + 1312.

2⁸⁵⁷⁸⁴² is an apocalyptic number.

857842 is a deficient number, since it is larger than the sum of its proper divisors (433658).

857842 is a wasteful number, since it uses less digits than its factorization.

857842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1580.

The product of its digits is 17920, while the sum is 34.

The square root of 857842 is about 926.1976031064. The cubic root of 857842 is about 95.0172452534.

The spelling of 857842 in words is "eight hundred fifty-seven thousand, eight hundred forty-two".