21144305239 has 4 divisors (see below), whose sum is σ = 21182960824. Its totient is φ = 21105649656.

The previous prime is 21144305167. The next prime is 21144305243. The reversal of 21144305239 is 93250344112.

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 21144305239 - 2⁷ = 21144305111 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21144305269) 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, 19326972 + ... + 19328065.

It is an arithmetic number, because the mean of its divisors is an integer number (5295740206).

Almost surely, 2^21144305239 is an apocalyptic number.

21144305239 is a deficient number, since it is larger than the sum of its proper divisors (38655585).

21144305239 is an equidigital number, since it uses as much as digits as its factorization.

21144305239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38655584.

The product of its (nonzero) digits is 25920, while the sum is 34.

The spelling of 21144305239 in words is "twenty-one billion, one hundred forty-four million, three hundred five thousand, two hundred thirty-nine".