821241 has 6 divisors (see below), whose sum is σ = 1186250. Its totient is φ = 547488.

The previous prime is 821209. The next prime is 821263. The reversal of 821241 is 142128.

It can be written as a sum of positive squares in only one way, i.e., 435600 + 385641 = 660^2 + 621^2 .

It is not a de Polignac number, because 821241 - 2⁵ = 821209 is a prime.

It is a Duffinian number.

It is a Curzon number.

821241 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (821281) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 45616 + ... + 45633.

2⁸²¹²⁴¹ is an apocalyptic number.

It is an amenable number.

821241 is a deficient number, since it is larger than the sum of its proper divisors (365009).

821241 is a wasteful number, since it uses less digits than its factorization.

821241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91255 (or 91252 counting only the distinct ones).

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

The square root of 821241 is about 906.2234823707. The cubic root of 821241 is about 93.6462104716.

Adding to 821241 its reverse (142128), we get a palindrome (963369).

The spelling of 821241 in words is "eight hundred twenty-one thousand, two hundred forty-one".