• 858 can be written using four 4's:

See also 113.

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858 has 16 divisors (see below), whose sum is σ = 2016. Its totient is φ = 240.

The previous prime is 857. The next prime is 859.

858 is nontrivially palindromic in base 10, base 14 and base 15.

858 is an esthetic number in base 14, because in such base its adjacent digits differ by 1.

It is an interprime number because it is at equal distance from previous prime (857) and next prime (859).

It is an alternating number because its digits alternate between even and odd.

858 is an undulating number in base 10, base 14 and base 15.

It is a plaindrome in base 7 and base 16.

It is a nialpdrome in base 11 and base 13.

It is not an unprimeable number, because it can be changed into a prime (853) 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, 60 + ... + 72.

It is an arithmetic number, because the mean of its divisors is an integer number (126).

858 is a Giuga number.

It is a practical number, because each smaller number is the sum of distinct divisors of 858, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1008).

858 is an abundant number, since it is smaller than the sum of its proper divisors (1158).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

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

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

The sum of its prime factors is 29.

The product of its digits is 320, while the sum is 21.

The square root of 858 is about 29.2916370318. The cubic root of 858 is about 9.5023078419.

It can be divided in two parts, 8 and 58, that multiplied together give a palindrome (464).

The spelling of 858 in words is "eight hundred fifty-eight", and thus it is an aban number and an oban number.