21732100 has 72 divisors (see below), whose sum is σ = 51706760. Its totient is φ = 7879680.

The previous prime is 21732089. The next prime is 21732101. The reversal of 21732100 is 123712.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 3873024 + 17859076 = 1968^2 + 4226^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21732101) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 94786 + ... + 95014.

Almost surely, 2^21732100 is an apocalyptic number.

21732100 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 21732100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25853380).

21732100 is an abundant number, since it is smaller than the sum of its proper divisors (29974660).

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

21732100 is a wasteful number, since it uses less digits than its factorization.

21732100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329 (or 322 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 16.

The square root of 21732100 is about 4661.7700500990. The cubic root of 21732100 is about 279.0619116382.

Adding to 21732100 its reverse (123712), we get a palindrome (21855812).

The spelling of 21732100 in words is "twenty-one million, seven hundred thirty-two thousand, one hundred".