21489600 has 252 divisors, whose sum is σ = 79590392. Its totient is φ = 5068800.

The previous prime is 21489599. The next prime is 21489607. The reversal of 21489600 is 698412.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21489607) 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 35 ways as a sum of consecutive naturals, for example, 580782 + ... + 580818.

Almost surely, 2^21489600 is an apocalyptic number.

21489600 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 21489600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39795196).

21489600 is an abundant number, since it is smaller than the sum of its proper divisors (58100792).

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

21489600 is a wasteful number, since it uses less digits than its factorization.

21489600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 21489600 is about 4635.6876512552. The cubic root of 21489600 is about 278.0200458261.

The spelling of 21489600 in words is "twenty-one million, four hundred eighty-nine thousand, six hundred".