858421 has 4 divisors (see below), whose sum is σ = 886144. Its totient is φ = 830700.

The previous prime is 858397. The next prime is 858427. The reversal of 858421 is 124858.

858421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 858421 - 2⁷ = 858293 is a prime.

It is a super-2 number, since 2×858421² = 1473773226482, which contains 22 as substring.

It is a Duffinian number.

858421 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 858421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (858427) 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, 13815 + ... + 13876.

It is an arithmetic number, because the mean of its divisors is an integer number (221536).

2⁸⁵⁸⁴²¹ is an apocalyptic number.

It is an amenable number.

858421 is a deficient number, since it is larger than the sum of its proper divisors (27723).

858421 is a wasteful number, since it uses less digits than its factorization.

858421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27722.

The product of its digits is 2560, while the sum is 28.

The square root of 858421 is about 926.5101186711. The cubic root of 858421 is about 95.0386177253.

The spelling of 858421 in words is "eight hundred fifty-eight thousand, four hundred twenty-one".