21202680 has 64 divisors (see below), whose sum is σ = 64231200. Its totient is φ = 5598720.

The previous prime is 21202669. The next prime is 21202681. The reversal of 21202680 is 8620212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202681) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12270 + ... + 13890.

Almost surely, 2^21202680 is an apocalyptic number.

21202680 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 21202680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32115600).

21202680 is an abundant number, since it is smaller than the sum of its proper divisors (43028520).

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

21202680 is a wasteful number, since it uses less digits than its factorization.

21202680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1744 (or 1740 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 21202680 is about 4604.6367934941. The cubic root of 21202680 is about 276.7771626831. Note that the first 3 decimals are identical.

Adding to 21202680 its reverse (8620212), we get a palindrome (29822892).

The spelling of 21202680 in words is "twenty-one million, two hundred two thousand, six hundred eighty".