21541608 has 96 divisors (see below), whose sum is σ = 64864800. Its totient is φ = 6403200.

The previous prime is 21541607. The next prime is 21541631. The reversal of 21541608 is 80614512.

21541608 is a `hidden beast` number, since 2 + 1 + 54 + 1 + 608 = 666.

It is not an unprimeable number, because it can be changed into a prime (21541607) 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 23 ways as a sum of consecutive naturals, for example, 46498 + ... + 46958.

It is an arithmetic number, because the mean of its divisors is an integer number (675675).

Almost surely, 2^21541608 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 21541608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32432400).

21541608 is an abundant number, since it is smaller than the sum of its proper divisors (43323192).

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

21541608 is a wasteful number, since it uses less digits than its factorization.

21541608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543 (or 536 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 21541608 is about 4641.2937851422. The cubic root of 21541608 is about 278.2441483017.

The spelling of 21541608 in words is "twenty-one million, five hundred forty-one thousand, six hundred eight".