261136655 has 32 divisors (see below), whose sum is σ = 346248000. Its totient is φ = 187886592.

The previous prime is 261136637. The next prime is 261136657. The reversal of 261136655 is 556631162.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261136655 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261136657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 571187 + ... + 571643.

It is an arithmetic number, because the mean of its divisors is an integer number (10820250).

Almost surely, 2^261136655 is an apocalyptic number.

261136655 is a deficient number, since it is larger than the sum of its proper divisors (85111345).

261136655 is a wasteful number, since it uses less digits than its factorization.

261136655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 683.

The product of its digits is 32400, while the sum is 35.

The square root of 261136655 is about 16159.7232340161. The cubic root of 261136655 is about 639.1791682330.

It can be divided in two parts, 26113 and 6655, that added together give a 15-th power (32768 = 2¹⁵).

The spelling of 261136655 in words is "two hundred sixty-one million, one hundred thirty-six thousand, six hundred fifty-five".