21455441 has 8 divisors (see below), whose sum is σ = 25311744. Its totient is φ = 17796960.

The previous prime is 21455431. The next prime is 21455443. The reversal of 21455441 is 14455412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21455441 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21455441.

It is not an unprimeable number, because it can be changed into a prime (21455443) 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 7 ways as a sum of consecutive naturals, for example, 49220 + ... + 49653.

It is an arithmetic number, because the mean of its divisors is an integer number (3163968).

Almost surely, 2^21455441 is an apocalyptic number.

It is an amenable number.

21455441 is a deficient number, since it is larger than the sum of its proper divisors (3856303).

21455441 is an equidigital number, since it uses as much as digits as its factorization.

21455441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98911.

The product of its digits is 3200, while the sum is 26.

The square root of 21455441 is about 4632.0018350601. The cubic root of 21455441 is about 277.8726578934.

It can be divided in two parts, 214 and 55441, that added together give a palindrome (55655).

The spelling of 21455441 in words is "twenty-one million, four hundred fifty-five thousand, four hundred forty-one".