21044402123 has 8 divisors (see below), whose sum is σ = 21712881600. Its totient is φ = 20385975168.

The previous prime is 21044402101. The next prime is 21044402149. The reversal of 21044402123 is 32120444012.

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

It is a cyclic number.

It is not a de Polignac number, because 21044402123 - 2⁸ = 21044401867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21044402623) 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, 2508878 + ... + 2517251.

It is an arithmetic number, because the mean of its divisors is an integer number (2714110200).

Almost surely, 2^21044402123 is an apocalyptic number.

21044402123 is a deficient number, since it is larger than the sum of its proper divisors (668479477).

21044402123 is an equidigital number, since it uses as much as digits as its factorization.

21044402123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5026261.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21044402123 its reverse (32120444012), we get a palindrome (53164846135).

The spelling of 21044402123 in words is "twenty-one billion, forty-four million, four hundred two thousand, one hundred twenty-three".