81705203 has 4 divisors (see below), whose sum is σ = 83605368. Its totient is φ = 79805040.

The previous prime is 81705191. The next prime is 81705229. The reversal of 81705203 is 30250718.

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 81705203 - 2¹⁶ = 81639667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81705703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 950018 + ... + 950103.

It is an arithmetic number, because the mean of its divisors is an integer number (20901342).

Almost surely, 2^81705203 is an apocalyptic number.

81705203 is a deficient number, since it is larger than the sum of its proper divisors (1900165).

81705203 is a wasteful number, since it uses less digits than its factorization.

81705203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1900164.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 81705203 is about 9039.0930407868. The cubic root of 81705203 is about 433.9268973690.

The spelling of 81705203 in words is "eighty-one million, seven hundred five thousand, two hundred three".