21169636 has 12 divisors (see below), whose sum is σ = 37091628. Its totient is φ = 10572032.

The previous prime is 21169633. The next prime is 21169639. The reversal of 21169636 is 63696112.

It is an interprime number because it is at equal distance from previous prime (21169633) and next prime (21169639).

It can be written as a sum of positive squares in 2 ways, for example, as 10929636 + 10240000 = 3306^2 + 3200^2 .

It is not an unprimeable number, because it can be changed into a prime (21169633) 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, 1200 + ... + 6616.

It is an arithmetic number, because the mean of its divisors is an integer number (3090969).

Almost surely, 2^21169636 is an apocalyptic number.

It is an amenable number.

21169636 is a deficient number, since it is larger than the sum of its proper divisors (15921992).

21169636 is a wasteful number, since it uses less digits than its factorization.

21169636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6398 (or 6396 counting only the distinct ones).

The product of its digits is 11664, while the sum is 34.

The square root of 21169636 is about 4601.0472720893. The cubic root of 21169636 is about 276.6333038269.

The spelling of 21169636 in words is "twenty-one million, one hundred sixty-nine thousand, six hundred thirty-six".