21044255 has 8 divisors (see below), whose sum is σ = 25287552. Its totient is φ = 16812448.

The previous prime is 21044251. The next prime is 21044263. The reversal of 21044255 is 55244012.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21044255 - 2² = 21044251 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 21044255.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21044251) 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, 1877 + ... + 6753.

It is an arithmetic number, because the mean of its divisors is an integer number (3160944).

Almost surely, 2^21044255 is an apocalyptic number.

21044255 is a deficient number, since it is larger than the sum of its proper divisors (4243297).

21044255 is an equidigital number, since it uses as much as digits as its factorization.

21044255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5745.

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 21044255 is about 4587.4017700655. The cubic root of 21044255 is about 276.0860851333.

Adding to 21044255 its reverse (55244012), we get a palindrome (76288267).

The spelling of 21044255 in words is "twenty-one million, forty-four thousand, two hundred fifty-five".