21744311959 has 4 divisors (see below), whose sum is σ = 22331996104. Its totient is φ = 21156627816.

The previous prime is 21744311957. The next prime is 21744312011. The reversal of 21744311959 is 95911344712.

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 21744311959 - 2¹ = 21744311957 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 (21744311957) 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, 293842017 + ... + 293842090.

It is an arithmetic number, because the mean of its divisors is an integer number (5582999026).

Almost surely, 2^21744311959 is an apocalyptic number.

21744311959 is a deficient number, since it is larger than the sum of its proper divisors (587684145).

21744311959 is an equidigital number, since it uses as much as digits as its factorization.

21744311959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 587684144.

The product of its digits is 272160, while the sum is 46.

The spelling of 21744311959 in words is "twenty-one billion, seven hundred forty-four million, three hundred eleven thousand, nine hundred fifty-nine".