81195115 has 4 divisors (see below), whose sum is σ = 97434144. Its totient is φ = 64956088.

The previous prime is 81195109. The next prime is 81195161. The reversal of 81195115 is 51159118.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51159118 = 2 ⋅25579559.

It is a cyclic number.

It is not a de Polignac number, because 81195115 - 2⁷ = 81194987 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8119507 + ... + 8119516.

It is an arithmetic number, because the mean of its divisors is an integer number (24358536).

Almost surely, 2^81195115 is an apocalyptic number.

81195115 is a deficient number, since it is larger than the sum of its proper divisors (16239029).

81195115 is a wasteful number, since it uses less digits than its factorization.

81195115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16239028.

The product of its digits is 1800, while the sum is 31.

The square root of 81195115 is about 9010.8332023182. The cubic root of 81195115 is about 433.0220055060.

The spelling of 81195115 in words is "eighty-one million, one hundred ninety-five thousand, one hundred fifteen".