16721609664 has 28 divisors (see below), whose sum is σ = 44242592744. Its totient is φ = 5573869824.

The previous prime is 16721609651. The next prime is 16721609693. The reversal of 16721609664 is 46690612761.

16721609664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×16721609664² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

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, 43545667 + ... + 43546050.

It is an arithmetic number, because the mean of its divisors is an integer number (1580092598).

Almost surely, 2^16721609664 is an apocalyptic number.

It is an amenable number.

16721609664 is an abundant number, since it is smaller than the sum of its proper divisors (27520983080).

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

16721609664 is an equidigital number, since it uses as much as digits as its factorization.

16721609664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87091732 (or 87091722 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 48.

The spelling of 16721609664 in words is "sixteen billion, seven hundred twenty-one million, six hundred nine thousand, six hundred sixty-four".