81986486905 has 8 divisors (see below), whose sum is σ = 98386243200. Its totient is φ = 65587550256.

The previous prime is 81986486893. The next prime is 81986486927. The reversal of 81986486905 is 50968468918.

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

It is a cyclic number.

It is not a de Polignac number, because 81986486905 - 2¹¹ = 81986484857 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 7 ways as a sum of consecutive naturals, for example, 42256 + ... + 407134.

It is an arithmetic number, because the mean of its divisors is an integer number (12298280400).

Almost surely, 2^81986486905 is an apocalyptic number.

It is an amenable number.

81986486905 is a deficient number, since it is larger than the sum of its proper divisors (16399756295).

81986486905 is a wasteful number, since it uses less digits than its factorization.

81986486905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409823.

The product of its (nonzero) digits is 29859840, while the sum is 64.

The spelling of 81986486905 in words is "eighty-one billion, nine hundred eighty-six million, four hundred eighty-six thousand, nine hundred five".