21200636 has 12 divisors (see below), whose sum is σ = 37801512. Its totient is φ = 10400208.

The previous prime is 21200633. The next prime is 21200639. The reversal of 21200636 is 63600212.

It is an interprime number because it is at equal distance from previous prime (21200633) and next prime (21200639).

21200636 is a modest number, since divided by 636 gives 212 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49790 + ... + 50213.

It is an arithmetic number, because the mean of its divisors is an integer number (3150126).

Almost surely, 2^21200636 is an apocalyptic number.

It is an amenable number.

21200636 is a deficient number, since it is larger than the sum of its proper divisors (16600876).

21200636 is a wasteful number, since it uses less digits than its factorization.

21200636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100060 (or 100058 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 21200636 is about 4604.4148379572. The cubic root of 21200636 is about 276.7682683562.

Adding to 21200636 its reverse (63600212), we get a palindrome (84800848).

The spelling of 21200636 in words is "twenty-one million, two hundred thousand, six hundred thirty-six".