81423729339 has 8 divisors (see below), whose sum is σ = 108568903680. Its totient is φ = 54280520616.

The previous prime is 81423729323. The next prime is 81423729347. The reversal of 81423729339 is 93392732418.

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

It is not a de Polignac number, because 81423729339 - 2⁴ = 81423729323 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81423729291 and 81423729300.

It is not an unprimeable number, because it can be changed into a prime (81423729139) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 391867 + ... + 562500.

It is an arithmetic number, because the mean of its divisors is an integer number (13571112960).

Almost surely, 2^81423729339 is an apocalyptic number.

81423729339 is a deficient number, since it is larger than the sum of its proper divisors (27145174341).

81423729339 is a wasteful number, since it uses less digits than its factorization.

81423729339 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 982809.

The product of its digits is 1959552, while the sum is 51.

The spelling of 81423729339 in words is "eighty-one billion, four hundred twenty-three million, seven hundred twenty-nine thousand, three hundred thirty-nine".