21744311989 has 4 divisors (see below), whose sum is σ = 22445741440. Its totient is φ = 21042882540.

The previous prime is 21744311957. The next prime is 21744312011. The reversal of 21744311989 is 98911344712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21744311989 - 2⁵ = 21744311957 is a prime.

It is a super-2 number, since 2×21744311989² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21744311489) 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, 350714679 + ... + 350714740.

It is an arithmetic number, because the mean of its divisors is an integer number (5611435360).

Almost surely, 2^21744311989 is an apocalyptic number.

It is an amenable number.

21744311989 is a deficient number, since it is larger than the sum of its proper divisors (701429451).

21744311989 is an equidigital number, since it uses as much as digits as its factorization.

21744311989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 701429450.

The product of its digits is 435456, while the sum is 49.

The spelling of 21744311989 in words is "twenty-one billion, seven hundred forty-four million, three hundred eleven thousand, nine hundred eighty-nine".