81093439 has 8 divisors (see below), whose sum is σ = 92759040. Its totient is φ = 69448056.

The previous prime is 81093413. The next prime is 81093457. The reversal of 81093439 is 93439018.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81093439 - 2¹¹ = 81091391 is a prime.

It is a super-2 number, since 2×81093439² = 13152291697693442, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81093398 and 81093407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81093409) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4842 + ... + 13624.

It is an arithmetic number, because the mean of its divisors is an integer number (11594880).

Almost surely, 2^81093439 is an apocalyptic number.

81093439 is a deficient number, since it is larger than the sum of its proper divisors (11665601).

81093439 is a wasteful number, since it uses less digits than its factorization.

81093439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10109.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 81093439 is about 9005.1895593596. The cubic root of 81093439 is about 432.8411804399.

It can be divided in two parts, 810 and 93439, that added together give a palindrome (94249).

The spelling of 81093439 in words is "eighty-one million, ninety-three thousand, four hundred thirty-nine".