261798 has 8 divisors (see below), whose sum is σ = 523608. Its totient is φ = 87264.

The previous prime is 261791. The next prime is 261799. The reversal of 261798 is 897162.

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

261798 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261791) by changing a digit.

261798 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 3 ways as a sum of consecutive naturals, for example, 21811 + ... + 21822.

It is an arithmetic number, because the mean of its divisors is an integer number (65451).

2²⁶¹⁷⁹⁸ is an apocalyptic number.

261798 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261798 is a wasteful number, since it uses less digits than its factorization.

261798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43638.

The product of its digits is 6048, while the sum is 33.

The square root of 261798 is about 511.6619978071. The cubic root of 261798 is about 63.9718300506.

The spelling of 261798 in words is "two hundred sixty-one thousand, seven hundred ninety-eight".