21744311988 has 24 divisors (see below), whose sum is σ = 57984832192. Its totient is φ = 6212660544.

The previous prime is 21744311957. The next prime is 21744312011. The reversal of 21744311988 is 88911344712.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 129430345 + ... + 129430512.

Almost surely, 2^21744311988 is an apocalyptic number.

21744311988 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21744311988 is an abundant number, since it is smaller than the sum of its proper divisors (36240520204).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21744311988 is a wasteful number, since it uses less digits than its factorization.

21744311988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258860871 (or 258860869 counting only the distinct ones).

The product of its digits is 387072, while the sum is 48.

The spelling of 21744311988 in words is "twenty-one billion, seven hundred forty-four million, three hundred eleven thousand, nine hundred eighty-eight".