81728080403 has 4 divisors (see below), whose sum is σ = 81781744488. Its totient is φ = 81674416320.

The previous prime is 81728080393. The next prime is 81728080433. The reversal of 81728080403 is 30408082718.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81728080403 - 2⁴ = 81728080387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81728080433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26829758 + ... + 26832803.

It is an arithmetic number, because the mean of its divisors is an integer number (20445436122).

Almost surely, 2^81728080403 is an apocalyptic number.

81728080403 is a deficient number, since it is larger than the sum of its proper divisors (53664085).

81728080403 is a wasteful number, since it uses less digits than its factorization.

81728080403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53664084.

The product of its (nonzero) digits is 86016, while the sum is 41.

The spelling of 81728080403 in words is "eighty-one billion, seven hundred twenty-eight million, eighty thousand, four hundred three".