81011475081 has 16 divisors (see below), whose sum is σ = 125235131520. Its totient is φ = 51659490960.

The previous prime is 81011475073. The next prime is 81011475101. The reversal of 81011475081 is 18057411018.

81011475081 is a `hidden beast` number, since 8 + 1 + 0 + 1 + 147 + 508 + 1 = 666.

It is not a de Polignac number, because 81011475081 - 2³ = 81011475073 is a prime.

It is a super-2 number, since 2×81011475081² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81011475581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65226010 + ... + 65227251.

It is an arithmetic number, because the mean of its divisors is an integer number (7827195720).

Almost surely, 2^81011475081 is an apocalyptic number.

It is an amenable number.

81011475081 is a deficient number, since it is larger than the sum of its proper divisors (44223656439).

81011475081 is a wasteful number, since it uses less digits than its factorization.

81011475081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130453293 (or 130453287 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 36.

Adding to 81011475081 its reverse (18057411018), we get a palindrome (99068886099).

The spelling of 81011475081 in words is "eighty-one billion, eleven million, four hundred seventy-five thousand, eighty-one".