16721522017265 has 16 divisors (see below), whose sum is σ = 21779503915008. Its totient is φ = 12250970940096.

The previous prime is 16721522017253. The next prime is 16721522017397. The reversal of 16721522017265 is 56271022512761.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 16721522017265 - 2²⁶ = 16721454908401 is a prime.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1012803497 + ... + 1012820006.

It is an arithmetic number, because the mean of its divisors is an integer number (1361218994688).

Almost surely, 2^{16721522017265} is an apocalyptic number.

It is an amenable number.

16721522017265 is a deficient number, since it is larger than the sum of its proper divisors (5057981897743).

16721522017265 is a wasteful number, since it uses less digits than its factorization.

16721522017265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2025623648.

The product of its (nonzero) digits is 705600, while the sum is 47.

The spelling of 16721522017265 in words is "sixteen trillion, seven hundred twenty-one billion, five hundred twenty-two million, seventeen thousand, two hundred sixty-five".