261475855 has 32 divisors (see below), whose sum is σ = 336199680. Its totient is φ = 194866560.

The previous prime is 261475843. The next prime is 261475867. The reversal of 261475855 is 558574162.

It is an interprime number because it is at equal distance from previous prime (261475843) and next prime (261475867).

It is not a de Polignac number, because 261475855 - 2⁹ = 261475343 is a prime.

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, 728166 + ... + 728524.

It is an arithmetic number, because the mean of its divisors is an integer number (10506240).

Almost surely, 2^261475855 is an apocalyptic number.

261475855 is a deficient number, since it is larger than the sum of its proper divisors (74723825).

261475855 is a wasteful number, since it uses less digits than its factorization.

261475855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 559.

The product of its digits is 336000, while the sum is 43.

The square root of 261475855 is about 16170.2150573207. The cubic root of 261475855 is about 639.4557995974.

The spelling of 261475855 in words is "two hundred sixty-one million, four hundred seventy-five thousand, eight hundred fifty-five".