81191076 has 12 divisors (see below), whose sum is σ = 189445872. Its totient is φ = 27063688.

The previous prime is 81191057. The next prime is 81191083. The reversal of 81191076 is 67019118.

It is a tau number, because it is divible by the number of its divisors (12).

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, 3382950 + ... + 3382973.

It is an arithmetic number, because the mean of its divisors is an integer number (15787156).

Almost surely, 2^81191076 is an apocalyptic number.

It is an amenable number.

81191076 is an abundant number, since it is smaller than the sum of its proper divisors (108254796).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81191076 is a wasteful number, since it uses less digits than its factorization.

81191076 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6765930 (or 6765928 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 33.

The square root of 81191076 is about 9010.6090804118. The cubic root of 81191076 is about 433.0148252511.

The spelling of 81191076 in words is "eighty-one million, one hundred ninety-one thousand, seventy-six".