21043055 has 8 divisors (see below), whose sum is σ = 27547344. Its totient is φ = 15304000.

The previous prime is 21043037. The next prime is 21043069. The reversal of 21043055 is 55034012.

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

It is not a de Polignac number, because 21043055 - 2¹⁶ = 20977519 is a prime.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 191246 + ... + 191355.

It is an arithmetic number, because the mean of its divisors is an integer number (3443418).

Almost surely, 2^21043055 is an apocalyptic number.

21043055 is a deficient number, since it is larger than the sum of its proper divisors (6504289).

21043055 is a wasteful number, since it uses less digits than its factorization.

21043055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382617.

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 21043055 is about 4587.2709752096. The cubic root of 21043055 is about 276.0808373099.

Adding to 21043055 its reverse (55034012), we get a palindrome (76077067).

The spelling of 21043055 in words is "twenty-one million, forty-three thousand, fifty-five".