21716100 has 180 divisors, whose sum is σ = 80661504. Its totient is φ = 4950720.

The previous prime is 21716087. The next prime is 21716137. The reversal of 21716100 is 161712.

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (18).

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 59 ways as a sum of consecutive naturals, for example, 56509 + ... + 56891.

Almost surely, 2^21716100 is an apocalyptic number.

21716100 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 21716100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40330752).

21716100 is an abundant number, since it is smaller than the sum of its proper divisors (58945404).

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

21716100 is a wasteful number, since it uses less digits than its factorization.

21716100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416 (or 400 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 18.

The square root of 21716100 is about 4660.0536477599. The cubic root of 21716100 is about 278.9934094871.

Adding to 21716100 its reverse (161712), we get a palindrome (21877812).

The spelling of 21716100 in words is "twenty-one million, seven hundred sixteen thousand, one hundred".