81728435 has 8 divisors (see below), whose sum is σ = 103843296. Its totient is φ = 61536640.

The previous prime is 81728389. The next prime is 81728459. The reversal of 81728435 is 53482718.

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

It is not a de Polignac number, because 81728435 - 2⁶ = 81728371 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 480671 + ... + 480840.

It is an arithmetic number, because the mean of its divisors is an integer number (12980412).

Almost surely, 2^81728435 is an apocalyptic number.

81728435 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

81728435 is a deficient number, since it is larger than the sum of its proper divisors (22114861).

81728435 is a wasteful number, since it uses less digits than its factorization.

81728435 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 961533.

The product of its digits is 53760, while the sum is 38.

The square root of 81728435 is about 9040.3780341311. The cubic root of 81728435 is about 433.9680209612.

The spelling of 81728435 in words is "eighty-one million, seven hundred twenty-eight thousand, four hundred thirty-five".