221725 has 18 divisors (see below), whose sum is σ = 321594. Its totient is φ = 151200.

The previous prime is 221723. The next prime is 221729. The reversal of 221725 is 527122.

221725 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 1764 + 219961 = 42^2 + 469^2 .

It is not a de Polignac number, because 221725 - 2¹ = 221723 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221723) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1135 + ... + 1315.

2²²¹⁷²⁵ is an apocalyptic number.

221725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221725 is a deficient number, since it is larger than the sum of its proper divisors (99869).

221725 is a wasteful number, since it uses less digits than its factorization.

221725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205 (or 193 counting only the distinct ones).

The product of its digits is 280, while the sum is 19.

The square root of 221725 is about 470.8768416476. The cubic root of 221725 is about 60.5254770553.

Subtracting from 221725 its product of digits (280), we obtain a triangular number (221445 = T₆₆₅).

Adding to 221725 its reverse (527122), we get a palindrome (748847).

It can be divided in two parts, 221 and 725, that added together give a triangular number (946 = T₄₃).

The spelling of 221725 in words is "two hundred twenty-one thousand, seven hundred twenty-five".