81564111170 has 8 divisors (see below), whose sum is σ = 146815400124. Its totient is φ = 32625644464.

The previous prime is 81564111163. The next prime is 81564111199. The reversal of 81564111170 is 7111146518.

It can be written as a sum of positive squares in 2 ways, for example, as 76411886329 + 5152224841 = 276427^2 + 71779^2 .

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 81564111170.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4078205549 + ... + 4078205568.

Almost surely, 2^81564111170 is an apocalyptic number.

81564111170 is a deficient number, since it is larger than the sum of its proper divisors (65251288954).

81564111170 is a wasteful number, since it uses less digits than its factorization.

81564111170 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8156411124.

The product of its (nonzero) digits is 6720, while the sum is 35.

Adding to 81564111170 its reverse (7111146518), we get a palindrome (88675257688).

The spelling of 81564111170 in words is "eighty-one billion, five hundred sixty-four million, one hundred eleven thousand, one hundred seventy".