21461680768 has 32 divisors (see below), whose sum is σ = 46642576320. Its totient is φ = 9755308800.

The previous prime is 21461680763. The next prime is 21461680781. The reversal of 21461680768 is 86708616412.

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (21461680763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7619928 + ... + 7622743.

It is an arithmetic number, because the mean of its divisors is an integer number (1457580510).

Almost surely, 2^21461680768 is an apocalyptic number.

It is an amenable number.

21461680768 is an abundant number, since it is smaller than the sum of its proper divisors (25180895552).

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

21461680768 is a wasteful number, since it uses less digits than its factorization.

21461680768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15242696 (or 15242684 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 49.

The spelling of 21461680768 in words is "twenty-one billion, four hundred sixty-one million, six hundred eighty thousand, seven hundred sixty-eight".