216426 has 16 divisors (see below), whose sum is σ = 494784. Its totient is φ = 61824.

The previous prime is 216421. The next prime is 216431. The reversal of 216426 is 624612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (216421) and next prime (216431).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (216421) by changing a digit.

216426 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 7 ways as a sum of consecutive naturals, for example, 2535 + ... + 2618.

It is an arithmetic number, because the mean of its divisors is an integer number (30924).

2²¹⁶⁴²⁶ is an apocalyptic number.

216426 is an abundant number, since it is smaller than the sum of its proper divisors (278358).

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

216426 is a wasteful number, since it uses less digits than its factorization.

216426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5165.

The product of its digits is 576, while the sum is 21.

The square root of 216426 is about 465.2160788279. The cubic root of 216426 is about 60.0394185417.

The spelling of 216426 in words is "two hundred sixteen thousand, four hundred twenty-six".