81687422185 has 8 divisors (see below), whose sum is σ = 101187000576. Its totient is φ = 63241875120.

The previous prime is 81687422153. The next prime is 81687422189. The reversal of 81687422185 is 58122478618.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81687422185 - 2⁵ = 81687422153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81687422189) 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, 263507659 + ... + 263507968.

It is an arithmetic number, because the mean of its divisors is an integer number (12648375072).

Almost surely, 2^81687422185 is an apocalyptic number.

It is an amenable number.

81687422185 is a deficient number, since it is larger than the sum of its proper divisors (19499578391).

81687422185 is a wasteful number, since it uses less digits than its factorization.

81687422185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 527015663.

The product of its digits is 1720320, while the sum is 52.

The spelling of 81687422185 in words is "eighty-one billion, six hundred eighty-seven million, four hundred twenty-two thousand, one hundred eighty-five".