135665280 has 160 divisors (see below), whose sum is σ = 484670340. Its totient is φ = 36163584.

The previous prime is 135665279. The next prime is 135665291. The reversal of 135665280 is 82566531.

135665280 is a `hidden beast` number, since 13 + 566 + 5 + 2 + 80 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 127780416 + 7884864 = 11304^2 + 2808^2 .

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 50532 + ... + 53148.

Almost surely, 2^135665280 is an apocalyptic number.

135665280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 135665280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (242335170).

135665280 is an abundant number, since it is smaller than the sum of its proper divisors (349005060).

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

135665280 is an equidigital number, since it uses as much as digits as its factorization.

135665280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2648 (or 2627 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 135665280 is about 11647.5439471161. The cubic root of 135665280 is about 513.8340796908.

The spelling of 135665280 in words is "one hundred thirty-five million, six hundred sixty-five thousand, two hundred eighty".