135821568 has 144 divisors (see below), whose sum is σ = 390289536. Its totient is φ = 41779200.

The previous prime is 135821489. The next prime is 135821573. The reversal of 135821568 is 865128531.

Its product of digits (57600) is a multiple of the sum of its prime factors (240).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1318605 + ... + 1318707.

It is an arithmetic number, because the mean of its divisors is an integer number (2710344).

Almost surely, 2^135821568 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 135821568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (195144768).

135821568 is an abundant number, since it is smaller than the sum of its proper divisors (254467968).

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

135821568 is a wasteful number, since it uses less digits than its factorization.

135821568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240 (or 226 counting only the distinct ones).

The product of its digits is 57600, while the sum is 39.

The square root of 135821568 is about 11654.2510698886. The cubic root of 135821568 is about 514.0313182732.

The spelling of 135821568 in words is "one hundred thirty-five million, eight hundred twenty-one thousand, five hundred sixty-eight".