81767801636 has 12 divisors (see below), whose sum is σ = 143153020080. Its totient is φ = 40866938760.

The previous prime is 81767801623. The next prime is 81767801659. The reversal of 81767801636 is 63610876718.

It is a hoax number, since the sum of its digits (53) coincides with the sum of the digits of its distinct prime factors.

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 3 ways as a sum of consecutive naturals, for example, 4229666 + ... + 4248953.

It is an arithmetic number, because the mean of its divisors is an integer number (11929418340).

Almost surely, 2^81767801636 is an apocalyptic number.

It is an amenable number.

81767801636 is a deficient number, since it is larger than the sum of its proper divisors (61385218444).

81767801636 is a wasteful number, since it uses less digits than its factorization.

81767801636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8481034 (or 8481032 counting only the distinct ones).

The product of its (nonzero) digits is 2032128, while the sum is 53.

The spelling of 81767801636 in words is "eighty-one billion, seven hundred sixty-seven million, eight hundred one thousand, six hundred thirty-six".