215646 has 16 divisors (see below), whose sum is σ = 436224. Its totient is φ = 71064.

The previous prime is 215617. The next prime is 215653. The reversal of 215646 is 646512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 621 + ... + 903.

It is an arithmetic number, because the mean of its divisors is an integer number (27264).

2²¹⁵⁶⁴⁶ is an apocalyptic number.

215646 is an abundant number, since it is smaller than the sum of its proper divisors (220578).

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

215646 is a wasteful number, since it uses less digits than its factorization.

215646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415.

The product of its digits is 1440, while the sum is 24.

The square root of 215646 is about 464.3770020145. The cubic root of 215646 is about 59.9672042995.

It can be divided in two parts, 215 and 646, that added together give a triangular number (861 = T₄₁).

The spelling of 215646 in words is "two hundred fifteen thousand, six hundred forty-six".