21603936 has 48 divisors (see below), whose sum is σ = 57153600. Its totient is φ = 7145088.

The previous prime is 21603919. The next prime is 21603947. The reversal of 21603936 is 63930612.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12535 + ... + 14153.

It is an arithmetic number, because the mean of its divisors is an integer number (1190700).

Almost surely, 2^21603936 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 21603936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28576800).

21603936 is an abundant number, since it is smaller than the sum of its proper divisors (35549664).

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

21603936 is a wasteful number, since it uses less digits than its factorization.

21603936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1771 (or 1763 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 30.

The square root of 21603936 is about 4648.0034423395. The cubic root of 21603936 is about 278.5122450020.

The spelling of 21603936 in words is "twenty-one million, six hundred three thousand, nine hundred thirty-six".