21853412 has 18 divisors (see below), whose sum is σ = 44487702. Its totient is φ = 9365664.

The previous prime is 21853399. The next prime is 21853487. The reversal of 21853412 is 21435812.

It can be written as a sum of positive squares in only one way, i.e., 21473956 + 379456 = 4634^2 + 616^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 55553 + ... + 55944.

It is an arithmetic number, because the mean of its divisors is an integer number (2471539).

Almost surely, 2^21853412 is an apocalyptic number.

It is an amenable number.

21853412 is an abundant number, since it is smaller than the sum of its proper divisors (22634290).

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

21853412 is a wasteful number, since it uses less digits than its factorization.

21853412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111515 (or 111506 counting only the distinct ones).

The product of its digits is 1920, while the sum is 26.

The square root of 21853412 is about 4674.7633095163. The cubic root of 21853412 is about 279.5802042605.

The spelling of 21853412 in words is "twenty-one million, eight hundred fifty-three thousand, four hundred twelve".