21313441 has 4 divisors (see below), whose sum is σ = 21343252. Its totient is φ = 21283632.

The previous prime is 21313429. The next prime is 21313447. The reversal of 21313441 is 14431312.

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 19395216 + 1918225 = 4404^2 + 1385^2 .

It is a cyclic number.

It is not a de Polignac number, because 21313441 - 2¹¹ = 21311393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21313447) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13806 + ... + 15271.

It is an arithmetic number, because the mean of its divisors is an integer number (5335813).

Almost surely, 2^21313441 is an apocalyptic number.

It is an amenable number.

21313441 is a deficient number, since it is larger than the sum of its proper divisors (29811).

21313441 is an equidigital number, since it uses as much as digits as its factorization.

21313441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29810.

The product of its digits is 288, while the sum is 19.

The square root of 21313441 is about 4616.6482430439. The cubic root of 21313441 is about 277.2582793478.

Adding to 21313441 its reverse (14431312), we get a palindrome (35744753).

The spelling of 21313441 in words is "twenty-one million, three hundred thirteen thousand, four hundred forty-one".