21444123213 has 12 divisors (see below), whose sum is σ = 31275572640. Its totient is φ = 14157284616.

The previous prime is 21444123199. The next prime is 21444123223. The reversal of 21444123213 is 31232144412.

21444123213 is a `hidden beast` number, since 2 + 1 + 4 + 441 + 2 + 3 + 213 = 666.

It is not a de Polignac number, because 21444123213 - 2⁹ = 21444122701 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444123223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11565483 + ... + 11567336.

It is an arithmetic number, because the mean of its divisors is an integer number (2606297720).

Almost surely, 2^21444123213 is an apocalyptic number.

It is an amenable number.

21444123213 is a deficient number, since it is larger than the sum of its proper divisors (9831449427).

21444123213 is a wasteful number, since it uses less digits than its factorization.

21444123213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23132928 (or 23132925 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

Adding to 21444123213 its reverse (31232144412), we get a palindrome (52676267625).

The spelling of 21444123213 in words is "twenty-one billion, four hundred forty-four million, one hundred twenty-three thousand, two hundred thirteen".