81408733539 has 8 divisors (see below), whose sum is σ = 124051403520. Its totient is φ = 46519276296.

The previous prime is 81408733531. The next prime is 81408733559. The reversal of 81408733539 is 93533780418.

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

It is not a de Polignac number, because 81408733539 - 2³ = 81408733531 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81408733491 and 81408733500.

It is not an unprimeable number, because it can be changed into a prime (81408733531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1938303159 + ... + 1938303200.

It is an arithmetic number, because the mean of its divisors is an integer number (15506425440).

Almost surely, 2^81408733539 is an apocalyptic number.

81408733539 is a deficient number, since it is larger than the sum of its proper divisors (42642669981).

81408733539 is a wasteful number, since it uses less digits than its factorization.

81408733539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3876606369.

The product of its (nonzero) digits is 2177280, while the sum is 51.

The spelling of 81408733539 in words is "eighty-one billion, four hundred eight million, seven hundred thirty-three thousand, five hundred thirty-nine".