215826 has 16 divisors (see below), whose sum is σ = 465024. Its totient is φ = 66384.

The previous prime is 215801. The next prime is 215827. The reversal of 215826 is 628512.

215826 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an Ulam number.

It is a nialpdrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 215796 and 215805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215827) 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, 1306 + ... + 1461.

It is an arithmetic number, because the mean of its divisors is an integer number (29064).

2²¹⁵⁸²⁶ is an apocalyptic number.

215826 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

215826 is an abundant number, since it is smaller than the sum of its proper divisors (249198).

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

215826 is a wasteful number, since it uses less digits than its factorization.

215826 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2785.

The product of its digits is 960, while the sum is 24.

The square root of 215826 is about 464.5707696358. The cubic root of 215826 is about 59.9838845608.

Subtracting 215826 from its reverse (628512), we obtain a triangular number (412686 = T₉₀₈).

The spelling of 215826 in words is "two hundred fifteen thousand, eight hundred twenty-six".