16271808721 has 9 divisors (see below), whose sum is σ = 18929469321. Its totient is φ = 13946499252.

The previous prime is 16271808671. The next prime is 16271808731. The reversal of 16271808721 is 12780817261.

The square root of 16271808721 is 127561.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 16271808721 - 2¹¹ = 16271806673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16271808731) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 883816 + ... + 902038.

It is an arithmetic number, because the mean of its divisors is an integer number (2103274369).

Almost surely, 2^16271808721 is an apocalyptic number.

16271808721 is the 127561-st square number.

16271808721 is the 63781-st centered octagonal number.

It is an amenable number.

16271808721 is a deficient number, since it is larger than the sum of its proper divisors (2657660600).

16271808721 is an frugal number, since it uses more digits than its factorization.

16271808721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36460 (or 18230 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 43.

The spelling of 16271808721 in words is "sixteen billion, two hundred seventy-one million, eight hundred eight thousand, seven hundred twenty-one".