21008352 has 48 divisors (see below), whose sum is σ = 56201040. Its totient is φ = 6868992.

The previous prime is 21008347. The next prime is 21008353. The reversal of 21008352 is 25380012.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-4 number, since 4×21008352⁴ (a number of 30 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21008353) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3024 + ... + 7152.

It is an arithmetic number, because the mean of its divisors is an integer number (1170855).

Almost surely, 2^21008352 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 21008352, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28100520).

21008352 is an abundant number, since it is smaller than the sum of its proper divisors (35192688).

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

21008352 is a wasteful number, since it uses less digits than its factorization.

21008352 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4195 (or 4187 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 21008352 is about 4583.4868822764. The cubic root of 21008352 is about 275.9289882423.

Adding to 21008352 its reverse (25380012), we get a palindrome (46388364).

The spelling of 21008352 in words is "twenty-one million, eight thousand, three hundred fifty-two".