16643708478656 has 56 divisors (see below), whose sum is σ = 39386664188160. Its totient is φ = 6822886701312.

The previous prime is 16643708478629. The next prime is 16643708478673. The reversal of 16643708478656 is 65687480734661.

It is a tau number, because it is divible by the number of its divisors (56).

It is a self number, because there is not a number n which added to its sum of digits gives 16643708478656.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 807623066 + ... + 807643673.

Almost surely, 2^{16643708478656} is an apocalyptic number.

16643708478656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

16643708478656 is an abundant number, since it is smaller than the sum of its proper divisors (22742955709504).

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

16643708478656 is a wasteful number, since it uses less digits than its factorization.

16643708478656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1615266781 (or 1615266771 counting only the distinct ones).

The product of its (nonzero) digits is 975421440, while the sum is 71.

The spelling of 16643708478656 in words is "sixteen trillion, six hundred forty-three billion, seven hundred eight million, four hundred seventy-eight thousand, six hundred fifty-six".