261239167 has 18 divisors (see below), whose sum is σ = 308086184. Its totient is φ = 216991680.

The previous prime is 261239159. The next prime is 261239171. The reversal of 261239167 is 761932162.

It is not a de Polignac number, because 261239167 - 2³ = 261239159 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261239117) by changing a digit.

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 17 ways as a sum of consecutive naturals, for example, 1753209 + ... + 1753357.

Almost surely, 2^261239167 is an apocalyptic number.

261239167 is a deficient number, since it is larger than the sum of its proper divisors (46847017).

261239167 is an frugal number, since it uses more digits than its factorization.

261239167 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 387 (or 197 counting only the distinct ones).

The product of its digits is 27216, while the sum is 37.

The square root of 261239167 is about 16162.8947592936. The cubic root of 261239167 is about 639.2627961745.

The spelling of 261239167 in words is "two hundred sixty-one million, two hundred thirty-nine thousand, one hundred sixty-seven".