135217566 has 64 divisors (see below), whose sum is σ = 345081600. Its totient is φ = 38815200.

The previous prime is 135217561. The next prime is 135217571. The reversal of 135217566 is 665712531.

135217566 is a `hidden beast` number, since 1 + 3 + 521 + 75 + 66 = 666.

It is an interprime number because it is at equal distance from previous prime (135217561) and next prime (135217571).

It is a self number, because there is not a number n which added to its sum of digits gives 135217566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135217561) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5296 + ... + 17276.

It is an arithmetic number, because the mean of its divisors is an integer number (5391900).

Almost surely, 2^135217566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 135217566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (172540800).

135217566 is an abundant number, since it is smaller than the sum of its proper divisors (209864034).

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

135217566 is a wasteful number, since it uses less digits than its factorization.

135217566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12022 (or 12016 counting only the distinct ones).

The product of its digits is 37800, while the sum is 36.

The square root of 135217566 is about 11628.3088194286. The cubic root of 135217566 is about 513.2682158176.

The spelling of 135217566 in words is "one hundred thirty-five million, two hundred seventeen thousand, five hundred sixty-six".