221245 has 4 divisors (see below), whose sum is σ = 265500. Its totient is φ = 176992.

The previous prime is 221239. The next prime is 221251. The reversal of 221245 is 542122.

221245 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (221239) and next prime (221251).

It can be written as a sum of positive squares in 2 ways, for example, as 30276 + 190969 = 174^2 + 437^2 .

It is a cyclic number.

It is not a de Polignac number, because 221245 - 2¹⁷ = 90173 is a prime.

221245 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22120 + ... + 22129.

It is an arithmetic number, because the mean of its divisors is an integer number (66375).

2²²¹²⁴⁵ is an apocalyptic number.

It is an amenable number.

221245 is a deficient number, since it is larger than the sum of its proper divisors (44255).

221245 is an equidigital number, since it uses as much as digits as its factorization.

221245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44254.

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

The square root of 221245 is about 470.3668780856. The cubic root of 221245 is about 60.4817694314.

Adding to 221245 its reverse (542122), we get a palindrome (763367).

It can be divided in two parts, 221 and 245, that multiplied together give a palindrome (54145).

The spelling of 221245 in words is "two hundred twenty-one thousand, two hundred forty-five".