21585441 has 8 divisors (see below), whose sum is σ = 29450080. Its totient is φ = 14055552.

The previous prime is 21585439. The next prime is 21585493. The reversal of 21585441 is 14458512.

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

It is not a de Polignac number, because 21585441 - 2¹ = 21585439 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21585399 and 21585408.

It is not an unprimeable number, because it can be changed into a prime (21585041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83536 + ... + 83793.

It is an arithmetic number, because the mean of its divisors is an integer number (3681260).

Almost surely, 2^21585441 is an apocalyptic number.

It is an amenable number.

21585441 is a deficient number, since it is larger than the sum of its proper divisors (7864639).

21585441 is a wasteful number, since it uses less digits than its factorization.

21585441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167375.

The product of its digits is 6400, while the sum is 30.

The square root of 21585441 is about 4646.0134524127. The cubic root of 21585441 is about 278.4327447571.

The spelling of 21585441 in words is "twenty-one million, five hundred eighty-five thousand, four hundred forty-one".