21552464 has 60 divisors (see below), whose sum is σ = 45681600. Its totient is φ = 9844224.

The previous prime is 21552457. The next prime is 21552469. The reversal of 21552464 is 46425512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21552469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 272777 + ... + 272855.

It is an arithmetic number, because the mean of its divisors is an integer number (761360).

Almost surely, 2^21552464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21552464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22840800).

21552464 is an abundant number, since it is smaller than the sum of its proper divisors (24129136).

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

21552464 is a wasteful number, since it uses less digits than its factorization.

21552464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180 (or 157 counting only the distinct ones).

The product of its digits is 9600, while the sum is 29.

The square root of 21552464 is about 4642.4631393259. The cubic root of 21552464 is about 278.2908812908.

Adding to 21552464 its reverse (46425512), we get a palindrome (67977976).

The spelling of 21552464 in words is "twenty-one million, five hundred fifty-two thousand, four hundred sixty-four".