21723718016 has 384 divisors, whose sum is σ = 60392576160. Its totient is φ = 7648542720.

The previous prime is 21723717979. The next prime is 21723718019. The reversal of 21723718016 is 61081732712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21723718019) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 47535260 + ... + 47535716.

Almost surely, 2^21723718016 is an apocalyptic number.

21723718016 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21723718016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30196288080).

21723718016 is an abundant number, since it is smaller than the sum of its proper divisors (38668858144).

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

21723718016 is a wasteful number, since it uses less digits than its factorization.

21723718016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 562 (or 543 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 38.

The spelling of 21723718016 in words is "twenty-one billion, seven hundred twenty-three million, seven hundred eighteen thousand, sixteen".