221708 has 12 divisors (see below), whose sum is σ = 397320. Its totient is φ = 108192.

The previous prime is 221707. The next prime is 221713. The reversal of 221708 is 807122.

It is a self number, because there is not a number n which added to its sum of digits gives 221708.

It is not an unprimeable number, because it can be changed into a prime (221707) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 473 + ... + 816.

It is an arithmetic number, because the mean of its divisors is an integer number (33110).

2²²¹⁷⁰⁸ is an apocalyptic number.

It is an amenable number.

221708 is a deficient number, since it is larger than the sum of its proper divisors (175612).

221708 is a wasteful number, since it uses less digits than its factorization.

221708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1336 (or 1334 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 221708 is about 470.8587898723. The cubic root of 221708 is about 60.5239301550.

It can be divided in two parts, 221 and 708, that added together give a palindrome (929).

The spelling of 221708 in words is "two hundred twenty-one thousand, seven hundred eight".