261529 has 2 divisors, whose sum is σ = 261530. Its totient is φ = 261528.

The previous prime is 261523. The next prime is 261557. The reversal of 261529 is 925162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 198025 + 63504 = 445^2 + 252^2 .

It is a cyclic number.

It is not a de Polignac number, because 261529 - 2⁹ = 261017 is a prime.

It is a nialpdrome in base 8.

It is not a weakly prime, because it can be changed into another prime (261523) 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 as a sum of consecutive naturals, namely, 130764 + 130765.

It is an arithmetic number, because the mean of its divisors is an integer number (130765).

261529 is a Friedman number, since it can be written as (2+2)^9-615, using all its digits and the basic arithmetic operations.

2²⁶¹⁵²⁹ is an apocalyptic number.

It is an amenable number.

261529 is a deficient number, since it is larger than the sum of its proper divisors (1).

261529 is an equidigital number, since it uses as much as digits as its factorization.

261529 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1080, while the sum is 25.

The square root of 261529 is about 511.3990613992. The cubic root of 261529 is about 63.9499119820.

The spelling of 261529 in words is "two hundred sixty-one thousand, five hundred twenty-nine".