810073801681 has 9 divisors (see below), whose sum is σ = 812200760841. Its totient is φ = 807952405044.

The previous prime is 810073801661. The next prime is 810073801727. The reversal of 810073801681 is 186108370018.

The square root of 810073801681 is 900041.

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

It is not a de Polignac number, because 810073801681 - 2²⁵ = 810040247249 is a prime.

It is a super-2 number, since 2×810073801681² (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 (810073801601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 431118700 + ... + 431120578.

Almost surely, 2^810073801681 is an apocalyptic number.

810073801681 is the 900041-st square number.

810073801681 is the 450021-st centered octagonal number.

It is an amenable number.

810073801681 is a deficient number, since it is larger than the sum of its proper divisors (2126959160).

810073801681 is an frugal number, since it uses more digits than its factorization.

810073801681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4716 (or 2358 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 43.

The spelling of 810073801681 in words is "eight hundred ten billion, seventy-three million, eight hundred one thousand, six hundred eighty-one".