21123773344 has 96 divisors (see below), whose sum is σ = 45021795840. Its totient is φ = 9730406400.

The previous prime is 21123773329. The next prime is 21123773357. The reversal of 21123773344 is 44337732112.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2379474 + ... + 2388334.

It is an arithmetic number, because the mean of its divisors is an integer number (468977040).

Almost surely, 2^21123773344 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21123773344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22510897920).

21123773344 is an abundant number, since it is smaller than the sum of its proper divisors (23898022496).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21123773344 is a wasteful number, since it uses less digits than its factorization.

21123773344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9014 (or 9006 counting only the distinct ones).

The product of its digits is 84672, while the sum is 37.

The spelling of 21123773344 in words is "twenty-one billion, one hundred twenty-three million, seven hundred seventy-three thousand, three hundred forty-four".