21837836 has 6 divisors (see below), whose sum is σ = 38216220. Its totient is φ = 10918916.

The previous prime is 21837811. The next prime is 21837853. The reversal of 21837836 is 63873812.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21837836.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2729726 + ... + 2729733.

It is an arithmetic number, because the mean of its divisors is an integer number (6369370).

Almost surely, 2^21837836 is an apocalyptic number.

It is an amenable number.

21837836 is a deficient number, since it is larger than the sum of its proper divisors (16378384).

21837836 is a wasteful number, since it uses less digits than its factorization.

21837836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5459463 (or 5459461 counting only the distinct ones).

The product of its digits is 48384, while the sum is 38.

The square root of 21837836 is about 4673.0970458573. The cubic root of 21837836 is about 279.5137649590.

The spelling of 21837836 in words is "twenty-one million, eight hundred thirty-seven thousand, eight hundred thirty-six".