261605168 has 40 divisors (see below), whose sum is σ = 558345216. Its totient is φ = 117748800.

The previous prime is 261605161. The next prime is 261605173. The reversal of 261605168 is 861506162.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (261605161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10913 + ... + 25343.

Almost surely, 2^261605168 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 261605168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (279172608).

261605168 is an abundant number, since it is smaller than the sum of its proper divisors (296740048).

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

261605168 is a wasteful number, since it uses less digits than its factorization.

261605168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14553 (or 14547 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 261605168 is about 16174.2130565910. The cubic root of 261605168 is about 639.5611966077.

The spelling of 261605168 in words is "two hundred sixty-one million, six hundred five thousand, one hundred sixty-eight".