21787550880 has 192 divisors, whose sum is σ = 74441420928. Its totient is φ = 5334794240.

The previous prime is 21787550867. The next prime is 21787550887. The reversal of 21787550880 is 8805578712.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is not an unprimeable number, because it can be changed into a prime (21787550887) 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 31 ways as a sum of consecutive naturals, for example, 301999 + ... + 367121.

It is an arithmetic number, because the mean of its divisors is an integer number (387715734).

Almost surely, 2^21787550880 is an apocalyptic number.

21787550880 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 21787550880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37220710464).

21787550880 is an abundant number, since it is smaller than the sum of its proper divisors (52653870048).

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

21787550880 is a wasteful number, since it uses less digits than its factorization.

21787550880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65199 (or 65191 counting only the distinct ones).

The product of its (nonzero) digits is 1254400, while the sum is 51.

The spelling of 21787550880 in words is "twenty-one billion, seven hundred eighty-seven million, five hundred fifty thousand, eight hundred eighty".