221425 has 12 divisors (see below), whose sum is σ = 291276. Its totient is φ = 166400.

The previous prime is 221413. The next prime is 221447. The reversal of 221425 is 524122.

221425 = T₆₈ + T₆₉ + ... + T₁₁₇.

221425 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 6 ways, for example, as 2401 + 219024 = 49^2 + 468^2 .

It is not a de Polignac number, because 221425 - 2⁵ = 221393 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221399 and 221408.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 165 + ... + 685.

It is an arithmetic number, because the mean of its divisors is an integer number (24273).

2²²¹⁴²⁵ is an apocalyptic number.

221425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221425 is a deficient number, since it is larger than the sum of its proper divisors (69851).

221425 is a wasteful number, since it uses less digits than its factorization.

221425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 548 (or 543 counting only the distinct ones).

The product of its digits is 160, while the sum is 16.

The square root of 221425 is about 470.5581791872. The cubic root of 221425 is about 60.4981671917.

Adding to 221425 its reverse (524122), we get a palindrome (745547).

It can be divided in two parts, 221 and 425, that added together give a palindrome (646).

The spelling of 221425 in words is "two hundred twenty-one thousand, four hundred twenty-five".