21875636 has 12 divisors (see below), whose sum is σ = 38465280. Its totient is φ = 10885560.

The previous prime is 21875629. The next prime is 21875647. The reversal of 21875636 is 63657812.

It is a self number, because there is not a number n which added to its sum of digits gives 21875636.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12116 + ... + 13803.

It is an arithmetic number, because the mean of its divisors is an integer number (3205440).

Almost surely, 2^21875636 is an apocalyptic number.

It is an amenable number.

21875636 is a deficient number, since it is larger than the sum of its proper divisors (16589644).

21875636 is a wasteful number, since it uses less digits than its factorization.

21875636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26134 (or 26132 counting only the distinct ones).

The product of its digits is 60480, while the sum is 38.

The square root of 21875636 is about 4677.1397242332. The cubic root of 21875636 is about 279.6749459176.

The spelling of 21875636 in words is "twenty-one million, eight hundred seventy-five thousand, six hundred thirty-six".