21608552 has 32 divisors (see below), whose sum is σ = 46872000. Its totient is φ = 9147264.

The previous prime is 21608551. The next prime is 21608603. The reversal of 21608552 is 25580612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21608551) 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 7 ways as a sum of consecutive naturals, for example, 2324 + ... + 6972.

It is an arithmetic number, because the mean of its divisors is an integer number (1464750).

Almost surely, 2^21608552 is an apocalyptic number.

It is a pronic number, being equal to 4648×4649.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21608552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23436000).

21608552 is an abundant number, since it is smaller than the sum of its proper divisors (25263448).

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

21608552 is a wasteful number, since it uses less digits than its factorization.

21608552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4745 (or 4741 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 21608552 is about 4648.4999731096. The cubic root of 21608552 is about 278.5320796743.

The spelling of 21608552 in words is "twenty-one million, six hundred eight thousand, five hundred fifty-two".