81174215185 has 16 divisors (see below), whose sum is σ = 117183830400. Its totient is φ = 52732722816.

The previous prime is 81174215153. The next prime is 81174215197. The reversal of 81174215185 is 58151247118.

It is not a de Polignac number, because 81174215185 - 2⁵ = 81174215153 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61032580 + ... + 61033909.

It is an arithmetic number, because the mean of its divisors is an integer number (7323989400).

Almost surely, 2^81174215185 is an apocalyptic number.

It is an amenable number.

81174215185 is a deficient number, since it is larger than the sum of its proper divisors (36009615215).

81174215185 is a wasteful number, since it uses less digits than its factorization.

81174215185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122066520.

The product of its digits is 89600, while the sum is 43.

The spelling of 81174215185 in words is "eighty-one billion, one hundred seventy-four million, two hundred fifteen thousand, one hundred eighty-five".