21723280800 has 288 divisors, whose sum is σ = 77445668160. Its totient is φ = 5256192000.

The previous prime is 21723280793. The next prime is 21723280807. The reversal of 21723280800 is 808232712.

It is an interprime number because it is at equal distance from previous prime (21723280793) and next prime (21723280807).

It is not an unprimeable number, because it can be changed into a prime (21723280807) 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, 1834900 + ... + 1846700.

It is an arithmetic number, because the mean of its divisors is an integer number (268908570).

Almost surely, 2^21723280800 is an apocalyptic number.

21723280800 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 21723280800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38722834080).

21723280800 is an abundant number, since it is smaller than the sum of its proper divisors (55722387360).

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

21723280800 is a wasteful number, since it uses less digits than its factorization.

21723280800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11896 (or 11883 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 33.

The spelling of 21723280800 in words is "twenty-one billion, seven hundred twenty-three million, two hundred eighty thousand, eight hundred".