81178449 has 8 divisors (see below), whose sum is σ = 118077792. Its totient is φ = 49199040.

The previous prime is 81178441. The next prime is 81178459. The reversal of 81178449 is 94487118.

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

It is not a de Polignac number, because 81178449 - 2³ = 81178441 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 81178449.

It is not an unprimeable number, because it can be changed into a prime (81178441) 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, 1229944 + ... + 1230009.

It is an arithmetic number, because the mean of its divisors is an integer number (14759724).

Almost surely, 2^81178449 is an apocalyptic number.

It is an amenable number.

81178449 is a deficient number, since it is larger than the sum of its proper divisors (36899343).

81178449 is a wasteful number, since it uses less digits than its factorization.

81178449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2459967.

The product of its digits is 64512, while the sum is 42.

The square root of 81178449 is about 9009.9083791124. The cubic root of 81178449 is about 432.9923763074.

The spelling of 81178449 in words is "eighty-one million, one hundred seventy-eight thousand, four hundred forty-nine".