21730433760 has 720 divisors, whose sum is σ = 93958658640. Its totient is φ = 4702924800.

The previous prime is 21730433749. The next prime is 21730433801. The reversal of 21730433760 is 6733403712.

21730433760 is a `hidden beast` number, since 2 + 17 + 304 + 337 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 12064860 + ... + 12066660.

It is an arithmetic number, because the mean of its divisors is an integer number (130498137).

Almost surely, 2^21730433760 is an apocalyptic number.

21730433760 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 21730433760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46979329320).

21730433760 is an abundant number, since it is smaller than the sum of its proper divisors (72228224880).

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

21730433760 is a wasteful number, since it uses less digits than its factorization.

21730433760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1861 (or 1837 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 36.

The spelling of 21730433760 in words is "twenty-one billion, seven hundred thirty million, four hundred thirty-three thousand, seven hundred sixty".