21777930720 has 576 divisors, whose sum is σ = 96292385280. Its totient is φ = 4352569344.

The previous prime is 21777930697. The next prime is 21777930721. The reversal of 21777930720 is 2703977712.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21777930721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2485387 + ... + 2494133.

It is an arithmetic number, because the mean of its divisors is an integer number (167174280).

Almost surely, 2^21777930720 is an apocalyptic number.

21777930720 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 21777930720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48146192640).

21777930720 is an abundant number, since it is smaller than the sum of its proper divisors (74514454560).

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

21777930720 is a wasteful number, since it uses less digits than its factorization.

21777930720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8807 (or 8796 counting only the distinct ones).

The product of its (nonzero) digits is 259308, while the sum is 45.

The spelling of 21777930720 in words is "twenty-one billion, seven hundred seventy-seven million, nine hundred thirty thousand, seven hundred twenty".