1728018040681 has 9 divisors (see below), whose sum is σ = 1789699070341. Its totient is φ = 1668394404544.

The previous prime is 1728018040669. The next prime is 1728018040687. The reversal of 1728018040681 is 1860408108271.

The square root of 1728018040681 is 1314541.

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

It can be written as a sum of positive squares in 4 ways, for example, as 20762216281 + 1707255824400 = 144091^2 + 1306620^2 .

It is not a de Polignac number, because 1728018040681 - 2³⁵ = 1693658302313 is a prime.

It is a super-2 number, since 2×1728018040681² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1728018040687) 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, 38099025 + ... + 38144353.

Almost surely, 2^{1728018040681} is an apocalyptic number.

1728018040681 is the 1314541-st square number.

1728018040681 is the 657271-st centered octagonal number.

It is an amenable number.

1728018040681 is a deficient number, since it is larger than the sum of its proper divisors (61681029660).

1728018040681 is an frugal number, since it uses more digits than its factorization.

1728018040681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90716 (or 45358 counting only the distinct ones).

The product of its (nonzero) digits is 172032, while the sum is 46.

The spelling of 1728018040681 in words is "one trillion, seven hundred twenty-eight billion, eighteen million, forty thousand, six hundred eighty-one".