81475715839 has 12 divisors (see below), whose sum is σ = 100353043584. Its totient is φ = 65728307904.

The previous prime is 81475715833. The next prime is 81475715899. The reversal of 81475715839 is 93851757418.

It is not a de Polignac number, because 81475715839 - 2¹³ = 81475707647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81475715833) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 48904159 + ... + 48905824.

It is an arithmetic number, because the mean of its divisors is an integer number (8362753632).

Almost surely, 2^81475715839 is an apocalyptic number.

81475715839 is a deficient number, since it is larger than the sum of its proper divisors (18877327745).

81475715839 is a wasteful number, since it uses less digits than its factorization.

81475715839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97810014 (or 97810007 counting only the distinct ones).

The product of its digits is 8467200, while the sum is 58.

The spelling of 81475715839 in words is "eighty-one billion, four hundred seventy-five million, seven hundred fifteen thousand, eight hundred thirty-nine".