81165801 has 8 divisors (see below), whose sum is σ = 108341280. Its totient is φ = 54050432.

The previous prime is 81165797. The next prime is 81165829. The reversal of 81165801 is 10856118.

It is a happy number.

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 81165801 - 2² = 81165797 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81165881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11775 + ... + 17348.

It is an arithmetic number, because the mean of its divisors is an integer number (13542660).

Almost surely, 2^81165801 is an apocalyptic number.

It is an amenable number.

81165801 is a deficient number, since it is larger than the sum of its proper divisors (27175479).

81165801 is a wasteful number, since it uses less digits than its factorization.

81165801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30055.

The product of its (nonzero) digits is 1920, while the sum is 30.

The square root of 81165801 is about 9009.2064578408. The cubic root of 81165801 is about 432.9698876950.

The spelling of 81165801 in words is "eighty-one million, one hundred sixty-five thousand, eight hundred one".