261481 has 6 divisors (see below), whose sum is σ = 287546. Its totient is φ = 237600.

The previous prime is 261467. The next prime is 261509. The reversal of 261481 is 184162.

It can be written as a sum of positive squares in only one way, i.e., 234256 + 27225 = 484^2 + 165^2 .

It is not a de Polignac number, because 261481 - 2⁷ = 261353 is a prime.

It is a super-2 number, since 2×261481² = 136744626722, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (261431) 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 5 ways as a sum of consecutive naturals, for example, 960 + ... + 1201.

2²⁶¹⁴⁸¹ is an apocalyptic number.

It is an amenable number.

261481 is a deficient number, since it is larger than the sum of its proper divisors (26065).

261481 is a wasteful number, since it uses less digits than its factorization.

261481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2183 (or 2172 counting only the distinct ones).

The product of its digits is 384, while the sum is 22.

The square root of 261481 is about 511.3521291635. The cubic root of 261481 is about 63.9459993711.

The spelling of 261481 in words is "two hundred sixty-one thousand, four hundred eighty-one".