213642 has 48 divisors (see below), whose sum is σ = 550368. Its totient is φ = 59040.

The previous prime is 213641. The next prime is 213649. The reversal of 213642 is 246312.

It is a happy number.

213642 is a `hidden beast` number, since 21 + 3 + 642 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nialpdrome in base 13.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 213642.

It is not an unprimeable number, because it can be changed into a prime (213641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2533 + ... + 2615.

It is an arithmetic number, because the mean of its divisors is an integer number (11466).

2²¹³⁶⁴² is an apocalyptic number.

213642 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 213642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (275184).

213642 is an abundant number, since it is smaller than the sum of its proper divisors (336726).

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

213642 is a wasteful number, since it uses less digits than its factorization.

213642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115 (or 112 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 213642 is about 462.2142360421. The cubic root of 213642 is about 59.7808673221.

Adding to 213642 its reverse (246312), we get a palindrome (459954).

It can be divided in two parts, 21 and 3642, that added together give a palindrome (3663).

The spelling of 213642 in words is "two hundred thirteen thousand, six hundred forty-two".