261489 has 8 divisors (see below), whose sum is σ = 352512. Its totient is φ = 172400.

The previous prime is 261467. The next prime is 261509. The reversal of 261489 is 984162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261489 is a prime.

It is an Ulam number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 261489.

It is not an unprimeable number, because it can be changed into a prime (261439) 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 7 ways as a sum of consecutive naturals, for example, 129 + ... + 734.

It is an arithmetic number, because the mean of its divisors is an integer number (44064).

2²⁶¹⁴⁸⁹ is an apocalyptic number.

It is an amenable number.

261489 is a deficient number, since it is larger than the sum of its proper divisors (91023).

261489 is a wasteful number, since it uses less digits than its factorization.

261489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 967.

The product of its digits is 3456, while the sum is 30.

The square root of 261489 is about 511.3599515019. The cubic root of 261489 is about 63.9466515062.

The spelling of 261489 in words is "two hundred sixty-one thousand, four hundred eighty-nine".