21328600 has 48 divisors (see below), whose sum is σ = 50666400. Its totient is φ = 8346240.

The previous prime is 21328597. The next prime is 21328603. The reversal of 21328600 is 682312.

It is an interprime number because it is at equal distance from previous prime (21328597) and next prime (21328603).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21328603) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8266 + ... + 10534.

It is an arithmetic number, because the mean of its divisors is an integer number (1055550).

Almost surely, 2^21328600 is an apocalyptic number.

21328600 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 21328600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25333200).

21328600 is an abundant number, since it is smaller than the sum of its proper divisors (29337800).

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

21328600 is a wasteful number, since it uses less digits than its factorization.

21328600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2332 (or 2323 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 21328600 is about 4618.2897267279. The cubic root of 21328600 is about 277.3239962853.

The spelling of 21328600 in words is "twenty-one million, three hundred twenty-eight thousand, six hundred".