261328 has 10 divisors (see below), whose sum is σ = 506354. Its totient is φ = 130656.

The previous prime is 261323. The next prime is 261329. The reversal of 261328 is 823162.

It can be written as a sum of positive squares in only one way, i.e., 166464 + 94864 = 408^2 + 308^2 .

It is a nialpdrome in base 8.

It is a junction number, because it is equal to n+sod(n) for n = 261299 and 261308.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8151 + ... + 8182.

2²⁶¹³²⁸ is an apocalyptic number.

It is an amenable number.

261328 is a deficient number, since it is larger than the sum of its proper divisors (245026).

261328 is a wasteful number, since it uses less digits than its factorization.

261328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16341 (or 16335 counting only the distinct ones).

The product of its digits is 576, while the sum is 22.

The square root of 261328 is about 511.2025039062. The cubic root of 261328 is about 63.9335247276.

The spelling of 261328 in words is "two hundred sixty-one thousand, three hundred twenty-eight".