21065585 has 32 divisors (see below), whose sum is σ = 28753920. Its totient is φ = 14731200.

The previous prime is 21065563. The next prime is 21065599. The reversal of 21065585 is 58556012.

It is not a de Polignac number, because 21065585 - 2¹⁴ = 21049201 is a prime.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 67580 + ... + 67890.

It is an arithmetic number, because the mean of its divisors is an integer number (898560).

Almost surely, 2^21065585 is an apocalyptic number.

It is an amenable number.

21065585 is a deficient number, since it is larger than the sum of its proper divisors (7688335).

21065585 is a wasteful number, since it uses less digits than its factorization.

21065585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389.

The product of its (nonzero) digits is 12000, while the sum is 32.

The square root of 21065585 is about 4589.7260266818. The cubic root of 21065585 is about 276.1793319235.

The spelling of 21065585 in words is "twenty-one million, sixty-five thousand, five hundred eighty-five".