81234309 has 16 divisors (see below), whose sum is σ = 116864384. Its totient is φ = 49896000.

The previous prime is 81234289. The next prime is 81234323. The reversal of 81234309 is 90343218.

It is not a de Polignac number, because 81234309 - 2¹² = 81230213 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81234389) 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 15 ways as a sum of consecutive naturals, for example, 22959 + ... + 26259.

It is an arithmetic number, because the mean of its divisors is an integer number (7304024).

Almost surely, 2^81234309 is an apocalyptic number.

It is an amenable number.

81234309 is a deficient number, since it is larger than the sum of its proper divisors (35630075).

81234309 is a wasteful number, since it uses less digits than its factorization.

81234309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3948.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 81234309 is about 9013.0077665561. The cubic root of 81234309 is about 433.0916695261.

The spelling of 81234309 in words is "eighty-one million, two hundred thirty-four thousand, three hundred nine".