81735673 has 4 divisors (see below), whose sum is σ = 83729268. Its totient is φ = 79742080.

The previous prime is 81735653. The next prime is 81735713. The reversal of 81735673 is 37653718.

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

It can be written as a sum of positive squares in 2 ways, for example, as 26337424 + 55398249 = 5132^2 + 7443^2 .

It is a cyclic number.

It is not a de Polignac number, because 81735673 - 2⁹ = 81735161 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81735653) 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 3 ways as a sum of consecutive naturals, for example, 996736 + ... + 996817.

It is an arithmetic number, because the mean of its divisors is an integer number (20932317).

Almost surely, 2^81735673 is an apocalyptic number.

It is an amenable number.

81735673 is a deficient number, since it is larger than the sum of its proper divisors (1993595).

81735673 is a wasteful number, since it uses less digits than its factorization.

81735673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1993594.

The product of its digits is 105840, while the sum is 40.

The square root of 81735673 is about 9040.7783403864. The cubic root of 81735673 is about 433.9808315488.

The spelling of 81735673 in words is "eighty-one million, seven hundred thirty-five thousand, six hundred seventy-three".