21541085 has 4 divisors (see below), whose sum is σ = 25849308. Its totient is φ = 17232864.

The previous prime is 21541061. The next prime is 21541097. The reversal of 21541085 is 58014512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2365444 + 19175641 = 1538^2 + 4379^2 .

It is a cyclic number.

It is not a de Polignac number, because 21541085 - 2⁶ = 21541021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2154104 + ... + 2154113.

It is an arithmetic number, because the mean of its divisors is an integer number (6462327).

Almost surely, 2^21541085 is an apocalyptic number.

It is an amenable number.

21541085 is a deficient number, since it is larger than the sum of its proper divisors (4308223).

21541085 is an equidigital number, since it uses as much as digits as its factorization.

21541085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4308222.

The product of its (nonzero) digits is 1600, while the sum is 26.

The square root of 21541085 is about 4641.2374427517. The cubic root of 21541085 is about 278.2418964910.

Adding to 21541085 its reverse (58014512), we get a palindrome (79555597).

The spelling of 21541085 in words is "twenty-one million, five hundred forty-one thousand, eighty-five".