81195711 has 4 divisors (see below), whose sum is σ = 108260952. Its totient is φ = 54130472.

The previous prime is 81195677. The next prime is 81195713. The reversal of 81195711 is 11759118.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81195711 - 2¹¹ = 81193663 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81195713) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13532616 + ... + 13532621.

It is an arithmetic number, because the mean of its divisors is an integer number (27065238).

Almost surely, 2^81195711 is an apocalyptic number.

81195711 is a deficient number, since it is larger than the sum of its proper divisors (27065241).

81195711 is a wasteful number, since it uses less digits than its factorization.

81195711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27065240.

The product of its digits is 2520, while the sum is 33.

The square root of 81195711 is about 9010.8662735610. The cubic root of 81195711 is about 433.0230650135.

The spelling of 81195711 in words is "eighty-one million, one hundred ninety-five thousand, seven hundred eleven".