21337608 has 64 divisors (see below), whose sum is σ = 57009600. Its totient is φ = 6635520.

The previous prime is 21337607. The next prime is 21337621. The reversal of 21337608 is 80673312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21337607) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32968 + ... + 33608.

It is an arithmetic number, because the mean of its divisors is an integer number (890775).

Almost surely, 2^21337608 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 21337608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28504800).

21337608 is an abundant number, since it is smaller than the sum of its proper divisors (35671992).

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

21337608 is a wasteful number, since it uses less digits than its factorization.

21337608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 742 (or 738 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 21337608 is about 4619.2648765794. The cubic root of 21337608 is about 277.3630328052.

It can be divided in two parts, 21337 and 608, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 21337608 in words is "twenty-one million, three hundred thirty-seven thousand, six hundred eight".