21730901760 has 324 divisors, whose sum is σ = 77903417592. Its totient is φ = 5592588288.

The previous prime is 21730901747. The next prime is 21730901779. The reversal of 21730901760 is 6710903712.

It is a happy number.

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 35 ways as a sum of consecutive naturals, for example, 9687199 + ... + 9689441.

Almost surely, 2^21730901760 is an apocalyptic number.

21730901760 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 21730901760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38951708796).

21730901760 is an abundant number, since it is smaller than the sum of its proper divisors (56172515832).

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

21730901760 is a wasteful number, since it uses less digits than its factorization.

21730901760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2328 (or 2282 counting only the distinct ones).

The product of its (nonzero) digits is 15876, while the sum is 36.

The spelling of 21730901760 in words is "twenty-one billion, seven hundred thirty million, nine hundred one thousand, seven hundred sixty".