81208093 has 4 divisors (see below), whose sum is σ = 81725500. Its totient is φ = 80690688.

The previous prime is 81208073. The next prime is 81208097. The reversal of 81208093 is 39080218.

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 13935289 + 67272804 = 3733^2 + 8202^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81208093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81208097) 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, 258468 + ... + 258781.

It is an arithmetic number, because the mean of its divisors is an integer number (20431375).

Almost surely, 2^81208093 is an apocalyptic number.

It is an amenable number.

81208093 is a deficient number, since it is larger than the sum of its proper divisors (517407).

81208093 is a wasteful number, since it uses less digits than its factorization.

81208093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 517406.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 81208093 is about 9011.5533067280. The cubic root of 81208093 is about 433.0450752855.

The spelling of 81208093 in words is "eighty-one million, two hundred eight thousand, ninety-three".