21723037440 has 576 divisors, whose sum is σ = 80903155200. Its totient is φ = 4920901632.

The previous prime is 21723037417. The next prime is 21723037451. The reversal of 21723037440 is 4473032712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 35093451 + ... + 35094069.

Almost surely, 2^21723037440 is an apocalyptic number.

21723037440 is a gapful number since it is divisible by the number (20) 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 21723037440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40451577600).

21723037440 is an abundant number, since it is smaller than the sum of its proper divisors (59180117760).

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

21723037440 is a wasteful number, since it uses less digits than its factorization.

21723037440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 712 (or 698 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 33.

The spelling of 21723037440 in words is "twenty-one billion, seven hundred twenty-three million, thirty-seven thousand, four hundred forty".