261686871 has 6 divisors (see below), whose sum is σ = 377992160. Its totient is φ = 174457908.

The previous prime is 261686837. The next prime is 261686881. The reversal of 261686871 is 178686162.

It is a happy number.

It is not a de Polignac number, because 261686871 - 2¹⁰ = 261685847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261686881) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 14538151 + ... + 14538168.

Almost surely, 2^261686871 is an apocalyptic number.

261686871 is a deficient number, since it is larger than the sum of its proper divisors (116305289).

261686871 is a wasteful number, since it uses less digits than its factorization.

261686871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29076325 (or 29076322 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 261686871 is about 16176.7385773524. The cubic root of 261686871 is about 639.6277710181.

The spelling of 261686871 in words is "two hundred sixty-one million, six hundred eighty-six thousand, eight hundred seventy-one".