241821 has 12 divisors (see below), whose sum is σ = 354172. Its totient is φ = 158976.

The previous prime is 241817. The next prime is 241823. The reversal of 241821 is 128142.

It can be written as a sum of positive squares in 2 ways, for example, as 72900 + 168921 = 270^2 + 411^2 .

It is not a de Polignac number, because 241821 - 2² = 241817 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 241794 and 241803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (241823) 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, 735 + ... + 1011.

2²⁴¹⁸²¹ is an apocalyptic number.

It is an amenable number.

241821 is a deficient number, since it is larger than the sum of its proper divisors (112351).

241821 is a wasteful number, since it uses less digits than its factorization.

241821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 380 (or 377 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

The square root of 241821 is about 491.7529867728. The cubic root of 241821 is about 62.3014284442.

Adding to 241821 its reverse (128142), we get a palindrome (369963).

The spelling of 241821 in words is "two hundred forty-one thousand, eight hundred twenty-one".