81789339 has 4 divisors (see below), whose sum is σ = 109052456. Its totient is φ = 54526224.

The previous prime is 81789317. The next prime is 81789341. The reversal of 81789339 is 93398718.

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

It is not a de Polignac number, because 81789339 - 2⁸ = 81789083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81785339) 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, 13631554 + ... + 13631559.

It is an arithmetic number, because the mean of its divisors is an integer number (27263114).

Almost surely, 2^81789339 is an apocalyptic number.

81789339 is a deficient number, since it is larger than the sum of its proper divisors (27263117).

81789339 is a wasteful number, since it uses less digits than its factorization.

81789339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27263116.

The product of its digits is 326592, while the sum is 48.

The square root of 81789339 is about 9043.7458500336. The cubic root of 81789339 is about 434.0757917991.

It can be divided in two parts, 81789 and 339, that added together give a palindrome (82128).

The spelling of 81789339 in words is "eighty-one million, seven hundred eighty-nine thousand, three hundred thirty-nine".