21444004023 has 16 divisors (see below), whose sum is σ = 32130147840. Its totient is φ = 12622557024.

The previous prime is 21444004013. The next prime is 21444004073. The reversal of 21444004023 is 32040044412.

It is a happy number.

It is not a de Polignac number, because 21444004023 - 2⁴ = 21444004007 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21444003984 and 21444004002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444004013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11952283 + ... + 11954076.

It is an arithmetic number, because the mean of its divisors is an integer number (2008134240).

Almost surely, 2^21444004023 is an apocalyptic number.

21444004023 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21444004023 is a deficient number, since it is larger than the sum of its proper divisors (10686143817).

21444004023 is a wasteful number, since it uses less digits than its factorization.

21444004023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23906398.

The product of its (nonzero) digits is 3072, while the sum is 24.

Adding to 21444004023 its reverse (32040044412), we get a palindrome (53484048435).

The spelling of 21444004023 in words is "twenty-one billion, four hundred forty-four million, four thousand, twenty-three".