21020600 has 48 divisors (see below), whose sum is σ = 49702920. Its totient is φ = 8265600.

The previous prime is 21020591. The next prime is 21020603. The reversal of 21020600 is 602012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11339 + ... + 13061.

Almost surely, 2^21020600 is an apocalyptic number.

21020600 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 21020600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24851460).

21020600 is an abundant number, since it is smaller than the sum of its proper divisors (28682320).

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

21020600 is a wasteful number, since it uses less digits than its factorization.

21020600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1800 (or 1791 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21020600 is about 4584.8227882875. The cubic root of 21020600 is about 275.9826005975.

Adding to 21020600 its reverse (602012), we get a palindrome (21622612).

The spelling of 21020600 in words is "twenty-one million, twenty thousand, six hundred".