81066047841 has 9 divisors (see below), whose sum is σ = 117096636241. Its totient is φ = 54043462452.

The previous prime is 81066047801. The next prime is 81066047851. The reversal of 81066047841 is 14874066018.

The square root of 81066047841 is 284721.

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

81066047841 is a `hidden beast` number, since 81 + 0 + 6 + 60 + 478 + 41 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 81066047841 - 2¹⁷ = 81065916769 is a prime.

It is a super-2 number, since 2×81066047841² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81066047801) 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, 806710 + ... + 901616.

Almost surely, 2^81066047841 is an apocalyptic number.

81066047841 is the 284721-st square number.

81066047841 is the 142361-st centered octagonal number.

It is an amenable number.

81066047841 is a deficient number, since it is larger than the sum of its proper divisors (36030588400).

81066047841 is an frugal number, since it uses more digits than its factorization.

81066047841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189820 (or 94910 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 45.

The spelling of 81066047841 in words is "eighty-one billion, sixty-six million, forty-seven thousand, eight hundred forty-one".