187798328681 has 6 divisors (see below), whose sum is σ = 192381618282. Its totient is φ = 183215174480.

The previous prime is 187798328677. The next prime is 187798328689. The reversal of 187798328681 is 186823897781.

It can be written as a sum of positive squares in only one way, i.e., 114511176025 + 73287152656 = 338395^2 + 270716^2 .

It is not a de Polignac number, because 187798328681 - 2² = 187798328677 is a prime.

It is a super-2 number, since 2×187798328681² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (187798328689) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2741000 + ... + 2808678.

It is an arithmetic number, because the mean of its divisors is an integer number (32063603047).

Almost surely, 2^187798328681 is an apocalyptic number.

It is an amenable number.

187798328681 is a deficient number, since it is larger than the sum of its proper divisors (4583289601).

187798328681 is an frugal number, since it uses more digits than its factorization.

187798328681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135399 (or 67720 counting only the distinct ones).

The product of its digits is 65028096, while the sum is 68.

The spelling of 187798328681 in words is "one hundred eighty-seven billion, seven hundred ninety-eight million, three hundred twenty-eight thousand, six hundred eighty-one".