21845047680 has 256 divisors, whose sum is σ = 77505638400. Its totient is φ = 5814982656.

The previous prime is 21845047643. The next prime is 21845047739. The reversal of 21845047680 is 8674054812.

21845047680 is a `hidden beast` number, since 2 + 1 + 84 + 504 + 7 + 68 + 0 = 666.

It is a super-2 number, since 2×21845047680² (a number of 21 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 18782779 + ... + 18783941.

It is an arithmetic number, because the mean of its divisors is an integer number (302756400).

Almost surely, 2^21845047680 is an apocalyptic number.

21845047680 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 21845047680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38752819200).

21845047680 is an abundant number, since it is smaller than the sum of its proper divisors (55660590720).

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

21845047680 is a wasteful number, since it uses less digits than its factorization.

21845047680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2278 (or 2260 counting only the distinct ones).

The product of its (nonzero) digits is 430080, while the sum is 45.

The spelling of 21845047680 in words is "twenty-one billion, eight hundred forty-five million, forty-seven thousand, six hundred eighty".