261636325 has 6 divisors (see below), whose sum is σ = 324429074. Its totient is φ = 209309040.

The previous prime is 261636317. The next prime is 261636371. The reversal of 261636325 is 523636162.

It can be written as a sum of positive squares in 3 ways, for example, as 22439169 + 239197156 = 4737^2 + 15466^2 .

It is not a de Polignac number, because 261636325 - 2³ = 261636317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 5232702 + ... + 5232751.

Almost surely, 2^261636325 is an apocalyptic number.

261636325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261636325 is a deficient number, since it is larger than the sum of its proper divisors (62792749).

261636325 is a wasteful number, since it uses less digits than its factorization.

261636325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10465463 (or 10465458 counting only the distinct ones).

The product of its digits is 38880, while the sum is 34.

The square root of 261636325 is about 16175.1761968765. The cubic root of 261636325 is about 639.5865860362.

The spelling of 261636325 in words is "two hundred sixty-one million, six hundred thirty-six thousand, three hundred twenty-five".