221286 has 16 divisors (see below), whose sum is σ = 476784. Its totient is φ = 68064.

The previous prime is 221281. The next prime is 221303. The reversal of 221286 is 682122.

221286 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221281) by changing a digit.

221286 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, 1341 + ... + 1496.

It is an arithmetic number, because the mean of its divisors is an integer number (29799).

2²²¹²⁸⁶ is an apocalyptic number.

221286 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

221286 is an abundant number, since it is smaller than the sum of its proper divisors (255498).

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

221286 is a wasteful number, since it uses less digits than its factorization.

221286 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2855.

The product of its digits is 384, while the sum is 21.

The square root of 221286 is about 470.4104590674. The cubic root of 221286 is about 60.4855052588.

The spelling of 221286 in words is "two hundred twenty-one thousand, two hundred eighty-six".