21055244339 has 4 divisors (see below), whose sum is σ = 21060662280. Its totient is φ = 21049826400.

The previous prime is 21055244323. The next prime is 21055244341. The reversal of 21055244339 is 93344255012.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21055244339 - 2⁴ = 21055244323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21055144339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2703137 + ... + 2710914.

It is an arithmetic number, because the mean of its divisors is an integer number (5265165570).

Almost surely, 2^21055244339 is an apocalyptic number.

21055244339 is a deficient number, since it is larger than the sum of its proper divisors (5417941).

21055244339 is an equidigital number, since it uses as much as digits as its factorization.

21055244339 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5417940.

The product of its (nonzero) digits is 129600, while the sum is 38.

The spelling of 21055244339 in words is "twenty-one billion, fifty-five million, two hundred forty-four thousand, three hundred thirty-nine".