261925 has 6 divisors (see below), whose sum is σ = 324818. Its totient is φ = 209520.

The previous prime is 261917. The next prime is 261959. The reversal of 261925 is 529162.

It can be written as a sum of positive squares in 3 ways, for example, as 37249 + 224676 = 193^2 + 474^2 .

It is not a de Polignac number, because 261925 - 2³ = 261917 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 10477 = 261925 / (2 + 6 + 1 + 9 + 2 + 5).

It is a Duffinian number.

261925 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 261925.

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, 5214 + ... + 5263.

2²⁶¹⁹²⁵ is an apocalyptic number.

261925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261925 is a deficient number, since it is larger than the sum of its proper divisors (62893).

261925 is a wasteful number, since it uses less digits than its factorization.

261925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10487 (or 10482 counting only the distinct ones).

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

The square root of 261925 is about 511.7860881267. The cubic root of 261925 is about 63.9821727691.

The spelling of 261925 in words is "two hundred sixty-one thousand, nine hundred twenty-five".