21010585 has 4 divisors (see below), whose sum is σ = 25212708. Its totient is φ = 16808464.

The previous prime is 21010579. The next prime is 21010601. The reversal of 21010585 is 58501012.

21010585 = 1445² + 1446² + ... + 1454².

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 12559936 + 8450649 = 3544^2 + 2907^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010585 - 2⁵ = 21010553 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian 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, 2101054 + ... + 2101063.

It is an arithmetic number, because the mean of its divisors is an integer number (6303177).

Almost surely, 2^21010585 is an apocalyptic number.

It is an amenable number.

21010585 is a deficient number, since it is larger than the sum of its proper divisors (4202123).

21010585 is an equidigital number, since it uses as much as digits as its factorization.

21010585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4202122.

The product of its (nonzero) digits is 400, while the sum is 22.

The square root of 21010585 is about 4583.7304676431. The cubic root of 21010585 is about 275.9387641574.

Adding to 21010585 its reverse (58501012), we get a palindrome (79511597).

The spelling of 21010585 in words is "twenty-one million, ten thousand, five hundred eighty-five".