21444123111 has 8 divisors (see below), whose sum is σ = 28717021680. Its totient is φ = 14233653312.

The previous prime is 21444123089. The next prime is 21444123157. The reversal of 21444123111 is 11132144412.

It is a happy number.

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

It is not a de Polignac number, because 21444123111 - 2⁹ = 21444122599 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444123161) 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, 15606390 + ... + 15607763.

It is an arithmetic number, because the mean of its divisors is an integer number (3589627710).

Almost surely, 2^21444123111 is an apocalyptic number.

21444123111 is a deficient number, since it is larger than the sum of its proper divisors (7272898569).

21444123111 is a wasteful number, since it uses less digits than its factorization.

21444123111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31214385.

The product of its digits is 768, while the sum is 24.

Adding to 21444123111 its reverse (11132144412), we get a palindrome (32576267523).

The spelling of 21444123111 in words is "twenty-one billion, four hundred forty-four million, one hundred twenty-three thousand, one hundred eleven".