215842 has 8 divisors (see below), whose sum is σ = 353232. Its totient is φ = 98100.

The previous prime is 215833. The next prime is 215843. The reversal of 215842 is 248512.

215842 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (22), and also a Moran number because the ratio is a prime number: 9811 = 215842 / (2 + 1 + 5 + 8 + 4 + 2).

It is not an unprimeable number, because it can be changed into a prime (215843) by changing a digit.

215842 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 3 ways as a sum of consecutive naturals, for example, 4884 + ... + 4927.

It is an arithmetic number, because the mean of its divisors is an integer number (44154).

2²¹⁵⁸⁴² is an apocalyptic number.

215842 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

215842 is a deficient number, since it is larger than the sum of its proper divisors (137390).

215842 is a wasteful number, since it uses less digits than its factorization.

215842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9824.

The product of its digits is 640, while the sum is 22.

The square root of 215842 is about 464.5879895133. The cubic root of 215842 is about 59.9853668018.

It can be divided in two parts, 2 and 15842, that multiplied together give a square (31684 = 178²).

The spelling of 215842 in words is "two hundred fifteen thousand, eight hundred forty-two".