857681 has 8 divisors (see below), whose sum is σ = 945984. Its totient is φ = 771120.

The previous prime is 857671. The next prime is 857687. The reversal of 857681 is 186758.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 857681 - 2¹⁴ = 841297 is a prime.

It is a super-2 number, since 2×857681² = 1471233395522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (857687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 755 + ... + 1511.

It is an arithmetic number, because the mean of its divisors is an integer number (118248).

2⁸⁵⁷⁶⁸¹ is an apocalyptic number.

It is an amenable number.

857681 is a deficient number, since it is larger than the sum of its proper divisors (88303).

857681 is a wasteful number, since it uses less digits than its factorization.

857681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 871.

The product of its digits is 13440, while the sum is 35.

The square root of 857681 is about 926.1106845297. The cubic root of 857681 is about 95.0113005948.

The spelling of 857681 in words is "eight hundred fifty-seven thousand, six hundred eighty-one".