81758289 has 4 divisors (see below), whose sum is σ = 109011056. Its totient is φ = 54505524.

The previous prime is 81758269. The next prime is 81758317. The reversal of 81758289 is 98285718.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 81758289 - 2⁷ = 81758161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81758249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13626379 + ... + 13626384.

It is an arithmetic number, because the mean of its divisors is an integer number (27252764).

Almost surely, 2^81758289 is an apocalyptic number.

It is an amenable number.

81758289 is a deficient number, since it is larger than the sum of its proper divisors (27252767).

81758289 is a wasteful number, since it uses less digits than its factorization.

81758289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27252766.

The product of its digits is 322560, while the sum is 48.

The square root of 81758289 is about 9042.0290311412. The cubic root of 81758289 is about 434.0208548948.

The spelling of 81758289 in words is "eighty-one million, seven hundred fifty-eight thousand, two hundred eighty-nine".