21016600 has 96 divisors (see below), whose sum is σ = 54840240. Its totient is φ = 7424000.

The previous prime is 21016577. The next prime is 21016601. The reversal of 21016600 is 661012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21016601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 90084 + ... + 90316.

Almost surely, 2^21016600 is an apocalyptic number.

21016600 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 21016600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27420120).

21016600 is an abundant number, since it is smaller than the sum of its proper divisors (33823640).

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

21016600 is a wasteful number, since it uses less digits than its factorization.

21016600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301 (or 292 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 21016600 is about 4584.3865456569. The cubic root of 21016600 is about 275.9650939543.

Adding to 21016600 its reverse (661012), we get a palindrome (21677612).

The spelling of 21016600 in words is "twenty-one million, sixteen thousand, six hundred".