135378725666 has 8 divisors (see below), whose sum is σ = 203083819164. Its totient is φ = 67684119280.

The previous prime is 135378725663. The next prime is 135378725717. The reversal of 135378725666 is 666527873531.

It can be written as a sum of positive squares in 2 ways, for example, as 128650625041 + 6728100625 = 358679^2 + 82025^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (135378725663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2589425 + ... + 2641188.

Almost surely, 2^135378725666 is an apocalyptic number.

135378725666 is a deficient number, since it is larger than the sum of its proper divisors (67705093498).

135378725666 is a wasteful number, since it uses less digits than its factorization.

135378725666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5243556.

The product of its digits is 38102400, while the sum is 59.

The spelling of 135378725666 in words is "one hundred thirty-five billion, three hundred seventy-eight million, seven hundred twenty-five thousand, six hundred sixty-six".