16720557664 has 48 divisors (see below), whose sum is σ = 34424103168. Its totient is φ = 7979500672.

The previous prime is 16720557629. The next prime is 16720557673. The reversal of 16720557664 is 46675502761.

It is a congruent number.

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, 319389 + ... + 368035.

It is an arithmetic number, because the mean of its divisors is an integer number (717168816).

Almost surely, 2^16720557664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16720557664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17212051584).

16720557664 is an abundant number, since it is smaller than the sum of its proper divisors (17703545504).

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

16720557664 is a wasteful number, since it uses less digits than its factorization.

16720557664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49147 (or 49139 counting only the distinct ones).

The product of its (nonzero) digits is 2116800, while the sum is 49.

The spelling of 16720557664 in words is "sixteen billion, seven hundred twenty million, five hundred fifty-seven thousand, six hundred sixty-four".