81171827204 has 48 divisors (see below), whose sum is σ = 153867588336. Its totient is φ = 37246272000.

The previous prime is 81171827161. The next prime is 81171827251. The reversal of 81171827204 is 40272817118.

It can be written as a sum of positive squares in 8 ways, for example, as 10160236804 + 71011590400 = 100798^2 + 266480^2 .

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 21930554 + ... + 21934254.

It is an arithmetic number, because the mean of its divisors is an integer number (3205574757).

Almost surely, 2^81171827204 is an apocalyptic number.

It is an amenable number.

81171827204 is a deficient number, since it is larger than the sum of its proper divisors (72695761132).

81171827204 is a wasteful number, since it uses less digits than its factorization.

81171827204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6056 (or 6054 counting only the distinct ones).

The product of its (nonzero) digits is 50176, while the sum is 41.

The spelling of 81171827204 in words is "eighty-one billion, one hundred seventy-one million, eight hundred twenty-seven thousand, two hundred four".