21108065280 has 176 divisors, whose sum is σ = 69842329920. Its totient is φ = 5434605568.

The previous prime is 21108065269. The next prime is 21108065327. The reversal of 21108065280 is 8256080112.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 421747 + ... + 469133.

It is an arithmetic number, because the mean of its divisors is an integer number (396831420).

Almost surely, 2^21108065280 is an apocalyptic number.

21108065280 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 21108065280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34921164960).

21108065280 is an abundant number, since it is smaller than the sum of its proper divisors (48734264640).

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

21108065280 is a wasteful number, since it uses less digits than its factorization.

21108065280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47444 (or 47426 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 33.

The spelling of 21108065280 in words is "twenty-one billion, one hundred eight million, sixty-five thousand, two hundred eighty".