81439684335786 has 16 divisors (see below), whose sum is σ = 186147849910464. Its totient is φ = 23268481238784.

The previous prime is 81439684335733. The next prime is 81439684335791. The reversal of 81439684335786 is 68753348693418.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 969520051575 + ... + 969520051658.

It is an arithmetic number, because the mean of its divisors is an integer number (11634240619404).

Almost surely, 2^{81439684335786} is an apocalyptic number.

81439684335786 is an abundant number, since it is smaller than the sum of its proper divisors (104708165574678).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81439684335786 is a wasteful number, since it uses less digits than its factorization.

81439684335786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1939040103245.

The product of its digits is 2508226560, while the sum is 75.

The spelling of 81439684335786 in words is "eighty-one trillion, four hundred thirty-nine billion, six hundred eighty-four million, three hundred thirty-five thousand, seven hundred eighty-six".