81530439 has 8 divisors (see below), whose sum is σ = 108967152. Its totient is φ = 54223680.

The previous prime is 81530437. The next prime is 81530441. The reversal of 81530439 is 93403518.

It is an interprime number because it is at equal distance from previous prime (81530437) and next prime (81530441).

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

It is not a de Polignac number, because 81530439 - 2¹ = 81530437 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81530431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31014 + ... + 33539.

It is an arithmetic number, because the mean of its divisors is an integer number (13620894).

Almost surely, 2^81530439 is an apocalyptic number.

81530439 is a deficient number, since it is larger than the sum of its proper divisors (27436713).

81530439 is a wasteful number, since it uses less digits than its factorization.

81530439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64977.

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 81530439 is about 9029.4207455407. The cubic root of 81530439 is about 433.6172927131.

The spelling of 81530439 in words is "eighty-one million, five hundred thirty thousand, four hundred thirty-nine".