81155329 has 8 divisors (see below), whose sum is σ = 81781128. Its totient is φ = 80532480.

The previous prime is 81155317. The next prime is 81155353. The reversal of 81155329 is 92355118.

It can be written as a sum of positive squares in 4 ways, for example, as 27279729 + 53875600 = 5223^2 + 7340^2 .

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 81155329 - 2⁹ = 81154817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81155294 and 81155303.

It is not an unprimeable number, because it can be changed into a prime (81155929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94269 + ... + 95125.

It is an arithmetic number, because the mean of its divisors is an integer number (10222641).

Almost surely, 2^81155329 is an apocalyptic number.

It is an amenable number.

81155329 is a deficient number, since it is larger than the sum of its proper divisors (625799).

81155329 is a wasteful number, since it uses less digits than its factorization.

81155329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1475.

The product of its digits is 10800, while the sum is 34.

The square root of 81155329 is about 9008.6252558312. The cubic root of 81155329 is about 432.9512663232.

The spelling of 81155329 in words is "eighty-one million, one hundred fifty-five thousand, three hundred twenty-nine".