135681728 has 56 divisors (see below), whose sum is σ = 331390752. Its totient is φ = 53673984.

The previous prime is 135681703. The next prime is 135681731. The reversal of 135681728 is 827186531.

It is a tau number, because it is divible by the number of its divisors (56).

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, 5825 + ... + 17472.

It is an arithmetic number, because the mean of its divisors is an integer number (5917692).

Almost surely, 2^135681728 is an apocalyptic number.

It is an amenable number.

135681728 is an abundant number, since it is smaller than the sum of its proper divisors (195709024).

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

135681728 is a wasteful number, since it uses less digits than its factorization.

135681728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23329 (or 23319 counting only the distinct ones).

The product of its digits is 80640, while the sum is 41.

The square root of 135681728 is about 11648.2499973172. The cubic root of 135681728 is about 513.8548445257.

The spelling of 135681728 in words is "one hundred thirty-five million, six hundred eighty-one thousand, seven hundred twenty-eight".