81728027279 has 16 divisors (see below), whose sum is σ = 84572814144. Its totient is φ = 78924499200.

The previous prime is 81728027267. The next prime is 81728027291. The reversal of 81728027279 is 97272082718.

It is an interprime number because it is at equal distance from previous prime (81728027267) and next prime (81728027291).

It is a cyclic number.

It is not a de Polignac number, because 81728027279 - 2⁴ = 81728027263 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81728027279.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81728027209) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16978277 + ... + 16983089.

It is an arithmetic number, because the mean of its divisors is an integer number (5285800884).

Almost surely, 2^81728027279 is an apocalyptic number.

81728027279 is a deficient number, since it is larger than the sum of its proper divisors (2844786865).

81728027279 is a wasteful number, since it uses less digits than its factorization.

81728027279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8978.

The product of its (nonzero) digits is 1580544, while the sum is 53.

The spelling of 81728027279 in words is "eighty-one billion, seven hundred twenty-eight million, twenty-seven thousand, two hundred seventy-nine".