261071166 has 16 divisors (see below), whose sum is σ = 540147600. Its totient is φ = 84022848.

The previous prime is 261071147. The next prime is 261071171. The reversal of 261071166 is 661170162.

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 7 ways as a sum of consecutive naturals, for example, 750031 + ... + 750378.

It is an arithmetic number, because the mean of its divisors is an integer number (33759225).

Almost surely, 2^261071166 is an apocalyptic number.

261071166 is an abundant number, since it is smaller than the sum of its proper divisors (279076434).

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

261071166 is a wasteful number, since it uses less digits than its factorization.

261071166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1500443.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 261071166 is about 16157.6968036908. The cubic root of 261071166 is about 639.1257317104.

The spelling of 261071166 in words is "two hundred sixty-one million, seventy-one thousand, one hundred sixty-six".