21143552 has 56 divisors (see below), whose sum is σ = 44234100. Its totient is φ = 10092544.

The previous prime is 21143537. The next prime is 21143569. The reversal of 21143552 is 25534112.

It can be written as a sum of positive squares in 2 ways, for example, as 20647936 + 495616 = 4544^2 + 704^2 .

Its product of digits (1200) is a multiple of the sum of its prime divisors (120).

It is a zygodrome in base 4.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 237524 + ... + 237612.

Almost surely, 2^21143552 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 21143552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22117050).

21143552 is an abundant number, since it is smaller than the sum of its proper divisors (23090548).

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

21143552 is an frugal number, since it uses more digits than its factorization.

21143552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144 (or 120 counting only the distinct ones).

The product of its digits is 1200, while the sum is 23.

The square root of 21143552 is about 4598.2118263516. The cubic root of 21143552 is about 276.5196399497.

Adding to 21143552 its reverse (25534112), we get a palindrome (46677664).

The spelling of 21143552 in words is "twenty-one million, one hundred forty-three thousand, five hundred fifty-two".