81661730092 has 24 divisors (see below), whose sum is σ = 149417968896. Its totient is φ = 38977942608.

The previous prime is 81661730089. The next prime is 81661730099. The reversal of 81661730092 is 29003716618.

It is not an unprimeable number, because it can be changed into a prime (81661730099) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 836058 + ... + 928609.

It is an arithmetic number, because the mean of its divisors is an integer number (6225748704).

Almost surely, 2^81661730092 is an apocalyptic number.

It is an amenable number.

81661730092 is a deficient number, since it is larger than the sum of its proper divisors (67756238804).

81661730092 is a wasteful number, since it uses less digits than its factorization.

81661730092 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1765197 (or 1765195 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 43.

The spelling of 81661730092 in words is "eighty-one billion, six hundred sixty-one million, seven hundred thirty thousand, ninety-two".