261085855 has 4 divisors (see below), whose sum is σ = 313303032. Its totient is φ = 208868680.

The previous prime is 261085831. The next prime is 261085871. The reversal of 261085855 is 558580162.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 261085855 - 2⁵ = 261085823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26108581 + ... + 26108590.

It is an arithmetic number, because the mean of its divisors is an integer number (78325758).

Almost surely, 2^261085855 is an apocalyptic number.

261085855 is a deficient number, since it is larger than the sum of its proper divisors (52217177).

261085855 is an equidigital number, since it uses as much as digits as its factorization.

261085855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52217176.

The product of its (nonzero) digits is 96000, while the sum is 40.

The square root of 261085855 is about 16158.1513484681. The cubic root of 261085855 is about 639.1377181507.

The spelling of 261085855 in words is "two hundred sixty-one million, eighty-five thousand, eight hundred fifty-five".