213858 has 18 divisors (see below), whose sum is σ = 467649. Its totient is φ = 70632.

The previous prime is 213847. The next prime is 213859. The reversal of 213858 is 858312.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 205209 + 8649 = 453^2 + 93^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=327.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 213858.

It is not an unprimeable number, because it can be changed into a prime (213859) by changing a digit.

213858 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1908 + ... + 2016.

2²¹³⁸⁵⁸ is an apocalyptic number.

213858 is an abundant number, since it is smaller than the sum of its proper divisors (253791).

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

213858 is a wasteful number, since it uses less digits than its factorization.

213858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226 (or 114 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 213858 is about 462.4478348960. The cubic root of 213858 is about 59.8010074289.

It can be divided in two parts, 21 and 3858, that multiplied together give a palindrome (81018).

The spelling of 213858 in words is "two hundred thirteen thousand, eight hundred fifty-eight".