81259199 has 12 divisors (see below), whose sum is σ = 94699800. Its totient is φ = 69522768.

The previous prime is 81259187. The next prime is 81259267. The reversal of 81259199 is 99195218.

It is a happy number.

It is not a de Polignac number, because 81259199 - 2⁴ = 81259183 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 (81259699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 33572 + ... + 35910.

It is an arithmetic number, because the mean of its divisors is an integer number (7891650).

Almost surely, 2^81259199 is an apocalyptic number.

81259199 is a deficient number, since it is larger than the sum of its proper divisors (13440601).

81259199 is a wasteful number, since it uses less digits than its factorization.

81259199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3062 (or 3055 counting only the distinct ones).

The product of its digits is 58320, while the sum is 44.

The square root of 81259199 is about 9014.3884429283. The cubic root of 81259199 is about 433.1358977634.

The spelling of 81259199 in words is "eighty-one million, two hundred fifty-nine thousand, one hundred ninety-nine".