21030585 has 16 divisors (see below), whose sum is σ = 33714240. Its totient is φ = 11194560.

The previous prime is 21030557. The next prime is 21030589. The reversal of 21030585 is 58503012.

It is not a de Polignac number, because 21030585 - 2⁵ = 21030553 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (21030589) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9351 + ... + 11379.

It is an arithmetic number, because the mean of its divisors is an integer number (2107140).

Almost surely, 2^21030585 is an apocalyptic number.

It is an amenable number.

21030585 is a deficient number, since it is larger than the sum of its proper divisors (12683655).

21030585 is a wasteful number, since it uses less digits than its factorization.

21030585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2728.

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 21030585 is about 4585.9115778654. The cubic root of 21030585 is about 276.0262918663.

Adding to 21030585 its reverse (58503012), we get a palindrome (79533597).

The spelling of 21030585 in words is "twenty-one million, thirty thousand, five hundred eighty-five".