21799936 has 44 divisors (see below), whose sum is σ = 44419900. Its totient is φ = 10690560.

The previous prime is 21799901. The next prime is 21799937. The reversal of 21799936 is 63999712.

It can be written as a sum of positive squares in 2 ways, for example, as 7054336 + 14745600 = 2656^2 + 3840^2 .

It is not an unprimeable number, because it can be changed into a prime (21799937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62290 + ... + 62638.

Almost surely, 2^21799936 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 21799936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22209950).

21799936 is an abundant number, since it is smaller than the sum of its proper divisors (22619964).

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

21799936 is an equidigital number, since it uses as much as digits as its factorization.

21799936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430 (or 412 counting only the distinct ones).

The product of its digits is 183708, while the sum is 46.

The square root of 21799936 is about 4669.0401583195. The cubic root of 21799936 is about 279.3519707523.

The spelling of 21799936 in words is "twenty-one million, seven hundred ninety-nine thousand, nine hundred thirty-six".