260821 has 8 divisors (see below), whose sum is σ = 288288. Its totient is φ = 234000.

The previous prime is 260809. The next prime is 260849. The reversal of 260821 is 128062.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 260821 - 2¹⁷ = 129749 is a prime.

260821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (260861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1351 + ... + 1531.

It is an arithmetic number, because the mean of its divisors is an integer number (36036).

2²⁶⁰⁸²¹ is an apocalyptic number.

It is an amenable number.

260821 is a deficient number, since it is larger than the sum of its proper divisors (27467).

260821 is a wasteful number, since it uses less digits than its factorization.

260821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 260821 is about 510.7063735651. The cubic root of 260821 is about 63.8921523503.

Adding to 260821 its reverse (128062), we get a palindrome (388883).

It can be divided in two parts, 260 and 821, that added together give a triangular number (1081 = T₄₆).

The spelling of 260821 in words is "two hundred sixty thousand, eight hundred twenty-one".