221541 has 4 divisors (see below), whose sum is σ = 295392. Its totient is φ = 147692.

The previous prime is 221539. The next prime is 221549. The reversal of 221541 is 145122.

221541 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221541 - 2¹ = 221539 is a prime.

It is a D-number.

221541 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 221541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36921 + ... + 36926.

It is an arithmetic number, because the mean of its divisors is an integer number (73848).

2²²¹⁵⁴¹ is an apocalyptic number.

It is an amenable number.

221541 is a deficient number, since it is larger than the sum of its proper divisors (73851).

221541 is an equidigital number, since it uses as much as digits as its factorization.

221541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73850.

The product of its digits is 80, while the sum is 15.

The square root of 221541 is about 470.6814209208. The cubic root of 221541 is about 60.5087299289.

Adding to 221541 its reverse (145122), we get a palindrome (366663).

It can be divided in two parts, 22154 and 1, that added together give a triangular number (22155 = T₂₁₀).

The spelling of 221541 in words is "two hundred twenty-one thousand, five hundred forty-one".