135661686441768 has 24 divisors (see below), whose sum is σ = 367417067446650. Its totient is φ = 45220562147232.

The previous prime is 135661686441751. The next prime is 135661686441773. The reversal of 135661686441768 is 867144686166531.

135661686441768 is a `hidden beast` number, since 1 + 3 + 5 + 6 + 61 + 68 + 6 + 441 + 7 + 68 = 666.

It can be written as a sum of positive squares in only one way, i.e., 115397481951684 + 20264204490084 = 10742322^2 + 4501578^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a hoax number, since the sum of its digits (72) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (72), and also a Moran number because the ratio is a prime number: 1884190089469 = 135661686441768 / (1 + 3 + 5 + 6 + 6 + 1 + 6 + 8 + 6 + 4 + 4 + 1 + 7 + 6 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 135661686441696 and 135661686441705.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 942095044663 + ... + 942095044806.

Almost surely, 2^{135661686441768} is an apocalyptic number.

135661686441768 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

135661686441768 is an abundant number, since it is smaller than the sum of its proper divisors (231755381004882).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

135661686441768 is a wasteful number, since it uses less digits than its factorization.

135661686441768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1884190089481 (or 1884190089474 counting only the distinct ones).

The product of its digits is 836075520, while the sum is 72.

The spelling of 135661686441768 in words is "one hundred thirty-five trillion, six hundred sixty-one billion, six hundred eighty-six million, four hundred forty-one thousand, seven hundred sixty-eight".