261411165 has 32 divisors (see below), whose sum is σ = 469100160. Its totient is φ = 138108672.

The previous prime is 261411151. The next prime is 261411181. The reversal of 261411165 is 561114162.

It is not a de Polignac number, because 261411165 - 2⁷ = 261411037 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 polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5397 + ... + 23493.

It is an arithmetic number, because the mean of its divisors is an integer number (14659380).

Almost surely, 2^261411165 is an apocalyptic number.

It is an amenable number.

261411165 is a deficient number, since it is larger than the sum of its proper divisors (207688995).

261411165 is a wasteful number, since it uses less digits than its factorization.

261411165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18218 (or 18212 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 261411165 is about 16168.2146509749. The cubic root of 261411165 is about 639.4030607476.

The spelling of 261411165 in words is "two hundred sixty-one million, four hundred eleven thousand, one hundred sixty-five".