221769 has 12 divisors (see below), whose sum is σ = 328692. Its totient is φ = 144000.

The previous prime is 221747. The next prime is 221773. The reversal of 221769 is 967122.

It can be written as a sum of positive squares in 2 ways, for example, as 90000 + 131769 = 300^2 + 363^2 .

It is not a de Polignac number, because 221769 - 2⁵ = 221737 is a prime.

It is a super-2 number, since 2×221769² = 98362978722, which contains 22 as substring.

It is a nialpdrome in base 8.

It is a zygodrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (221719) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69 + ... + 669.

It is an arithmetic number, because the mean of its divisors is an integer number (27391).

2²²¹⁷⁶⁹ is an apocalyptic number.

It is an amenable number.

221769 is a deficient number, since it is larger than the sum of its proper divisors (106923).

221769 is a wasteful number, since it uses less digits than its factorization.

221769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648 (or 645 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 221769 is about 470.9235606763. The cubic root of 221769 is about 60.5294804302.

It can be divided in two parts, 221 and 769, that added together give a triangular number (990 = T₄₄).

The spelling of 221769 in words is "two hundred twenty-one thousand, seven hundred sixty-nine".