21768012811680 has 96 divisors (see below), whose sum is σ = 68582341505664. Its totient is φ = 5803694324736.

The previous prime is 21768012811609. The next prime is 21768012811681. The reversal of 21768012811680 is 8611821086712.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (21768012811681) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1816012 + ... + 6843531.

It is an arithmetic number, because the mean of its divisors is an integer number (714399390684).

Almost surely, 2^{21768012811680} is an apocalyptic number.

21768012811680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21768012811680 is an abundant number, since it is smaller than the sum of its proper divisors (46814328693984).

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

21768012811680 is a wasteful number, since it uses less digits than its factorization.

21768012811680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8664798 (or 8664790 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 51.

The spelling of 21768012811680 in words is "twenty-one trillion, seven hundred sixty-eight billion, twelve million, eight hundred eleven thousand, six hundred eighty".