21700783680 has 224 divisors, whose sum is σ = 71369822208. Its totient is φ = 5580748800.

The previous prime is 21700783673. The next prime is 21700783681. The reversal of 21700783680 is 8638700712.

It is not an unprimeable number, because it can be changed into a prime (21700783681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9849459 + ... + 9851661.

Almost surely, 2^21700783680 is an apocalyptic number.

21700783680 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 21700783680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35684911104).

21700783680 is an abundant number, since it is smaller than the sum of its proper divisors (49669038528).

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

21700783680 is a wasteful number, since it uses less digits than its factorization.

21700783680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2585 (or 2575 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 42.

The spelling of 21700783680 in words is "twenty-one billion, seven hundred million, seven hundred eighty-three thousand, six hundred eighty".