81164578 has 8 divisors (see below), whose sum is σ = 132814800. Its totient is φ = 36892980.

The previous prime is 81164549. The next prime is 81164581. The reversal of 81164578 is 87546118.

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

It is a self number, because there is not a number n which added to its sum of digits gives 81164578.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1844628 + ... + 1844671.

It is an arithmetic number, because the mean of its divisors is an integer number (16601850).

Almost surely, 2^81164578 is an apocalyptic number.

81164578 is a deficient number, since it is larger than the sum of its proper divisors (51650222).

81164578 is a wasteful number, since it uses less digits than its factorization.

81164578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3689312.

The product of its digits is 53760, while the sum is 40.

The square root of 81164578 is about 9009.1385825727. The cubic root of 81164578 is about 432.9677130319.

The spelling of 81164578 in words is "eighty-one million, one hundred sixty-four thousand, five hundred seventy-eight".