21733530 has 128 divisors (see below), whose sum is σ = 67737600. Its totient is φ = 4333824.

The previous prime is 21733513. The next prime is 21733561. The reversal of 21733530 is 3533712.

It is a self number, because there is not a number n which added to its sum of digits gives 21733530.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 51661 + ... + 52079.

It is an arithmetic number, because the mean of its divisors is an integer number (529200).

Almost surely, 2^21733530 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21733530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33868800).

21733530 is an abundant number, since it is smaller than the sum of its proper divisors (46004070).

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

21733530 is a wasteful number, since it uses less digits than its factorization.

21733530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468.

The product of its (nonzero) digits is 1890, while the sum is 24.

The square root of 21733530 is about 4661.9234227945. The cubic root of 21733530 is about 279.0680323810.

The spelling of 21733530 in words is "twenty-one million, seven hundred thirty-three thousand, five hundred thirty".