21552000 has 128 divisors (see below), whose sum is σ = 71604000. Its totient is φ = 5734400.

The previous prime is 21551993. The next prime is 21552007. The reversal of 21552000 is 25512.

It is an interprime number because it is at equal distance from previous prime (21551993) and next prime (21552007).

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21552007) 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, 47776 + ... + 48224.

Almost surely, 2^21552000 is an apocalyptic number.

21552000 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 21552000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35802000).

21552000 is an abundant number, since it is smaller than the sum of its proper divisors (50052000).

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

21552000 is an equidigital number, since it uses as much as digits as its factorization.

21552000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481 (or 459 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 15.

The square root of 21552000 is about 4642.4131655853. The cubic root of 21552000 is about 278.2888841813.

Adding to 21552000 its reverse (25512), we get a palindrome (21577512).

The spelling of 21552000 in words is "twenty-one million, five hundred fifty-two thousand".