21648996 has 36 divisors (see below), whose sum is σ = 56206332. Its totient is φ = 7020864.

The previous prime is 21648947. The next prime is 21648997. The reversal of 21648996 is 69984612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17388900 + 4260096 = 4170^2 + 2064^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (21648997) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 6795 + ... + 9458.

It is an arithmetic number, because the mean of its divisors is an integer number (1561287).

Almost surely, 2^21648996 is an apocalyptic number.

It is an amenable number.

21648996 is an abundant number, since it is smaller than the sum of its proper divisors (34557336).

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

21648996 is a wasteful number, since it uses less digits than its factorization.

21648996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16300 (or 16295 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 21648996 is about 4652.8481599983. The cubic root of 21648996 is about 278.7057444136.

The spelling of 21648996 in words is "twenty-one million, six hundred forty-eight thousand, nine hundred ninety-six".