261135506 has 16 divisors (see below), whose sum is σ = 425621760. Its totient is φ = 119705040.

The previous prime is 261135503. The next prime is 261135509. The reversal of 261135506 is 605531162.

It is an interprime number because it is at equal distance from previous prime (261135503) and next prime (261135509).

It is not an unprimeable number, because it can be changed into a prime (261135503) 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 7 ways as a sum of consecutive naturals, for example, 109661 + ... + 112016.

It is an arithmetic number, because the mean of its divisors is an integer number (26601360).

Almost surely, 2^261135506 is an apocalyptic number.

261135506 is a deficient number, since it is larger than the sum of its proper divisors (164486254).

261135506 is a wasteful number, since it uses less digits than its factorization.

261135506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221729.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 261135506 is about 16159.6876826256. The cubic root of 261135506 is about 639.1782307698.

Adding to 261135506 its reverse (605531162), we get a palindrome (866666668).

The spelling of 261135506 in words is "two hundred sixty-one million, one hundred thirty-five thousand, five hundred six".