16721040728 has 32 divisors (see below), whose sum is σ = 36593164800. Its totient is φ = 7013687712.

The previous prime is 16721040691. The next prime is 16721040731. The reversal of 16721040728 is 82704012761.

It is a junction number, because it is equal to n+sod(n) for n = 16721040691 and 16721040700.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3173858 + ... + 3179121.

It is an arithmetic number, because the mean of its divisors is an integer number (1143536400).

Almost surely, 2^16721040728 is an apocalyptic number.

It is an amenable number.

16721040728 is an abundant number, since it is smaller than the sum of its proper divisors (19872124072).

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

16721040728 is a wasteful number, since it uses less digits than its factorization.

16721040728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6353039 (or 6353035 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 38.

The spelling of 16721040728 in words is "sixteen billion, seven hundred twenty-one million, forty thousand, seven hundred twenty-eight".