21444042423 has 8 divisors (see below), whose sum is σ = 29256988288. Its totient is φ = 13963562424.

The previous prime is 21444042401. The next prime is 21444042427. The reversal of 21444042423 is 32424044412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21444042423 - 2⁵ = 21444042391 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 (21444042427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83116315 + ... + 83116572.

It is an arithmetic number, because the mean of its divisors is an integer number (3657123536).

Almost surely, 2^21444042423 is an apocalyptic number.

21444042423 is a deficient number, since it is larger than the sum of its proper divisors (7812945865).

21444042423 is a wasteful number, since it uses less digits than its factorization.

21444042423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166232933.

The product of its (nonzero) digits is 24576, while the sum is 30.

Adding to 21444042423 its reverse (32424044412), we get a palindrome (53868086835).

The spelling of 21444042423 in words is "twenty-one billion, four hundred forty-four million, forty-two thousand, four hundred twenty-three".