81385166704 has 10 divisors (see below), whose sum is σ = 157683760520. Its totient is φ = 40692583344.

The previous prime is 81385166669. The next prime is 81385166743. The reversal of 81385166704 is 40766158318.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2543286444 + ... + 2543286475.

It is an arithmetic number, because the mean of its divisors is an integer number (15768376052).

Almost surely, 2^81385166704 is an apocalyptic number.

It is an amenable number.

81385166704 is a deficient number, since it is larger than the sum of its proper divisors (76298593816).

81385166704 is a wasteful number, since it uses less digits than its factorization.

81385166704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5086572927 (or 5086572921 counting only the distinct ones).

The product of its (nonzero) digits is 967680, while the sum is 49.

The spelling of 81385166704 in words is "eighty-one billion, three hundred eighty-five million, one hundred sixty-six thousand, seven hundred four".