261330165 has 32 divisors (see below), whose sum is σ = 480614400. Its totient is φ = 134568000.

The previous prime is 261330151. The next prime is 261330203. The reversal of 261330165 is 561033162.

261330165 is a `hidden beast` number, since 2 + 613 + 30 + 16 + 5 = 666.

It is not a de Polignac number, because 261330165 - 2¹⁸ = 261068021 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 29461 + ... + 37290.

It is an arithmetic number, because the mean of its divisors is an integer number (15019200).

Almost surely, 2^261330165 is an apocalyptic number.

It is an amenable number.

261330165 is a deficient number, since it is larger than the sum of its proper divisors (219284235).

261330165 is a wasteful number, since it uses less digits than its factorization.

261330165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66794 (or 66788 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 261330165 is about 16165.7095421141. The cubic root of 261330165 is about 639.3370128187.

The spelling of 261330165 in words is "two hundred sixty-one million, three hundred thirty thousand, one hundred sixty-five".