21052584 has 48 divisors (see below), whose sum is σ = 65164320. Its totient is φ = 6014880.

The previous prime is 21052583. The next prime is 21052597. The reversal of 21052584 is 48525012.

It is a happy number.

It is a super-2 number, since 2×21052584² = 886422586154112, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21052583) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20382 + ... + 21389.

It is an arithmetic number, because the mean of its divisors is an integer number (1357590).

Almost surely, 2^21052584 is an apocalyptic number.

21052584 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21052584 is an abundant number, since it is smaller than the sum of its proper divisors (44111736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21052584 is a wasteful number, since it uses less digits than its factorization.

21052584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41790 (or 41783 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 21052584 is about 4588.3094926127. The cubic root of 21052584 is about 276.1225039041.

Adding to 21052584 its reverse (48525012), we get a palindrome (69577596).

The spelling of 21052584 in words is "twenty-one million, fifty-two thousand, five hundred eighty-four".