21836900 has 36 divisors (see below), whose sum is σ = 47757360. Its totient is φ = 8666400.

The previous prime is 21836879. The next prime is 21836917. The reversal of 21836900 is 963812.

It is a super-2 number, since 2×21836900² = 953700403220000, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13115 + ... + 14685.

Almost surely, 2^21836900 is an apocalyptic number.

21836900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21836900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23878680).

21836900 is an abundant number, since it is smaller than the sum of its proper divisors (25920460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21836900 is a wasteful number, since it uses less digits than its factorization.

21836900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1724 (or 1717 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 21836900 is about 4672.9968970672. The cubic root of 21836900 is about 279.5097714525.

Adding to 21836900 its sum of digits (29), we get a square (21836929 = 4673²).

The spelling of 21836900 in words is "twenty-one million, eight hundred thirty-six thousand, nine hundred".