21483905 has 4 divisors (see below), whose sum is σ = 25780692. Its totient is φ = 17187120.

The previous prime is 21483901. The next prime is 21483907. The reversal of 21483905 is 50938412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16248961 + 5234944 = 4031^2 + 2288^2 .

It is not a de Polignac number, because 21483905 - 2² = 21483901 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21483901) 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 3 ways as a sum of consecutive naturals, for example, 2148386 + ... + 2148395.

It is an arithmetic number, because the mean of its divisors is an integer number (6445173).

Almost surely, 2^21483905 is an apocalyptic number.

It is an amenable number.

21483905 is a deficient number, since it is larger than the sum of its proper divisors (4296787).

21483905 is an equidigital number, since it uses as much as digits as its factorization.

21483905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4296786.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 21483905 is about 4635.0733543278. The cubic root of 21483905 is about 277.9954841148.

The spelling of 21483905 in words is "twenty-one million, four hundred eighty-three thousand, nine hundred five".