81195081 has 16 divisors (see below), whose sum is σ = 119190720. Its totient is φ = 48755520.

The previous prime is 81195073. The next prime is 81195091. The reversal of 81195081 is 18059118.

It is not a de Polignac number, because 81195081 - 2³ = 81195073 is a prime.

It is a super-2 number, since 2×81195081² = 13185282357193122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (81195001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7690 + ... + 14883.

It is an arithmetic number, because the mean of its divisors is an integer number (7449420).

Almost surely, 2^81195081 is an apocalyptic number.

It is an amenable number.

81195081 is a deficient number, since it is larger than the sum of its proper divisors (37995639).

81195081 is a wasteful number, since it uses less digits than its factorization.

81195081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22696.

The product of its (nonzero) digits is 2880, while the sum is 33.

The square root of 81195081 is about 9010.8313157000. The cubic root of 81195081 is about 433.0219450642.

The spelling of 81195081 in words is "eighty-one million, one hundred ninety-five thousand, eighty-one".