261306255 has 32 divisors (see below), whose sum is σ = 481010688. Its totient is φ = 118656000.

The previous prime is 261306251. The next prime is 261306257. The reversal of 261306255 is 552603162.

It is not a de Polignac number, because 261306255 - 2² = 261306251 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261306251) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7615 + ... + 24095.

It is an arithmetic number, because the mean of its divisors is an integer number (15031584).

Almost surely, 2^261306255 is an apocalyptic number.

261306255 is a deficient number, since it is larger than the sum of its proper divisors (219704433).

261306255 is a wasteful number, since it uses less digits than its factorization.

261306255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16647.

The product of its (nonzero) digits is 10800, while the sum is 30.

The square root of 261306255 is about 16164.9699968791. The cubic root of 261306255 is about 639.3175138397.

It can be divided in two parts, 26130 and 6255, that added together give a triangular number (32385 = T₂₅₄).

The spelling of 261306255 in words is "two hundred sixty-one million, three hundred six thousand, two hundred fifty-five".