857021 has 8 divisors (see below), whose sum is σ = 990144. Its totient is φ = 733120.

The previous prime is 857011. The next prime is 857027. The reversal of 857021 is 120758.

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 857021 - 2¹⁰ = 855997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (857027) 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, 2105 + ... + 2478.

It is an arithmetic number, because the mean of its divisors is an integer number (123768).

2⁸⁵⁷⁰²¹ is an apocalyptic number.

It is an amenable number.

857021 is a deficient number, since it is larger than the sum of its proper divisors (133123).

857021 is a wasteful number, since it uses less digits than its factorization.

857021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4611.

The product of its (nonzero) digits is 560, while the sum is 23.

The square root of 857021 is about 925.7542870546. The cubic root of 857021 is about 94.9869234079.

Adding to 857021 its reverse (120758), we get a palindrome (977779).

The spelling of 857021 in words is "eight hundred fifty-seven thousand, twenty-one".