81887134148 has 24 divisors (see below), whose sum is σ = 151759577592. Its totient is φ = 38528129024.

The previous prime is 81887134139. The next prime is 81887134169. The reversal of 81887134148 is 84143178818.

It can be written as a sum of positive squares in 4 ways, for example, as 10951203904 + 70935930244 = 104648^2 + 266338^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81887134148.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 278240 + ... + 491112.

It is an arithmetic number, because the mean of its divisors is an integer number (6323315733).

Almost surely, 2^81887134148 is an apocalyptic number.

It is an amenable number.

81887134148 is a deficient number, since it is larger than the sum of its proper divisors (69872443444).

81887134148 is a wasteful number, since it uses less digits than its factorization.

81887134148 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218551 (or 218549 counting only the distinct ones).

The product of its digits is 1376256, while the sum is 53.

The spelling of 81887134148 in words is "eighty-one billion, eight hundred eighty-seven million, one hundred thirty-four thousand, one hundred forty-eight".