21735936 has 120 divisors (see below), whose sum is σ = 64633140. Its totient is φ = 7028736.

The previous prime is 21735919. The next prime is 21735937. The reversal of 21735936 is 63953712.

It can be written as a sum of positive squares in 2 ways, for example, as 21678336 + 57600 = 4656^2 + 240^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 21735936.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21735937) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 244180 + ... + 244268.

Almost surely, 2^21735936 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 21735936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32316570).

21735936 is an abundant number, since it is smaller than the sum of its proper divisors (42897204).

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

21735936 is an equidigital number, since it uses as much as digits as its factorization.

21735936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166 (or 147 counting only the distinct ones).

The product of its digits is 34020, while the sum is 36.

The square root of 21735936 is about 4662.1814636498. The cubic root of 21735936 is about 279.0783300318.

The spelling of 21735936 in words is "twenty-one million, seven hundred thirty-five thousand, nine hundred thirty-six".