16000072000081 has 9 divisors (see below), whose sum is σ = 17325578059569. Its totient is φ = 14769249230736.

The previous prime is 16000072000063. The next prime is 16000072000273. The reversal of 16000072000081 is 18000027000061.

The square root of 16000072000081 is 4000009.

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

16000072000081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 7885094257681 + 8114977742400 = 2808041^2 + 2848680^2 .

It is not a de Polignac number, because 16000072000081 - 2⁵ = 16000072000049 is a prime.

It is a super-2 number, since 2×16000072000081² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16000072000061) 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, 51846271 + ... + 52153963.

It is an arithmetic number, because the mean of its divisors is an integer number (1925064228841).

Almost surely, 2^{16000072000081} is an apocalyptic number.

16000072000081 is the 4000009-th square number.

16000072000081 is the 2000005-th centered octagonal number.

It is an amenable number.

16000072000081 is a deficient number, since it is larger than the sum of its proper divisors (1325506059488).

16000072000081 is an frugal number, since it uses more digits than its factorization.

16000072000081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 615412 (or 307706 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 25.

Multiplying 16000072000081 by its sum of digits (25), we get a square (400001800002025 = 20000045²).

The spelling of 16000072000081 in words is "sixteen trillion, seventy-two million, eighty-one", and thus it is an aban number and an uban number.