261505682 has 8 divisors (see below), whose sum is σ = 393133500. Its totient is φ = 130461184.

The previous prime is 261505681. The next prime is 261505687. The reversal of 261505682 is 286505162.

It can be written as a sum of positive squares in 2 ways, for example, as 260467321 + 1038361 = 16139^2 + 1019^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (261505681) 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 3 ways as a sum of consecutive naturals, for example, 144707 + ... + 146502.

Almost surely, 2^261505682 is an apocalyptic number.

261505682 is a deficient number, since it is larger than the sum of its proper divisors (131627818).

261505682 is a wasteful number, since it uses less digits than its factorization.

261505682 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291660.

The product of its (nonzero) digits is 28800, while the sum is 35.

The square root of 261505682 is about 16171.1373131267. The cubic root of 261505682 is about 639.4801132802.

The spelling of 261505682 in words is "two hundred sixty-one million, five hundred five thousand, six hundred eighty-two".