21053583 has 6 divisors (see below), whose sum is σ = 30410744. Its totient is φ = 14035716.

The previous prime is 21053567. The next prime is 21053597. The reversal of 21053583 is 38535012.

It is not a de Polignac number, because 21053583 - 2⁴ = 21053567 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21053503) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1169635 + ... + 1169652.

Almost surely, 2^21053583 is an apocalyptic number.

21053583 is a deficient number, since it is larger than the sum of its proper divisors (9357161).

21053583 is a wasteful number, since it uses less digits than its factorization.

21053583 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2339293 (or 2339290 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 21053583 is about 4588.4183549454. The cubic root of 21053583 is about 276.1268714126.

Adding to 21053583 its reverse (38535012), we get a palindrome (59588595).

The spelling of 21053583 in words is "twenty-one million, fifty-three thousand, five hundred eighty-three".