261800 has 96 divisors (see below), whose sum is σ = 803520. Its totient is φ = 76800.

The previous prime is 261799. The next prime is 261823. The reversal of 261800 is 8162.

261800 = 116² + 117² + ... + 132².

261800 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a nialpdrome in base 4.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15392 + ... + 15408.

It is an arithmetic number, because the mean of its divisors is an integer number (8370).

2²⁶¹⁸⁰⁰ is an apocalyptic number.

261800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (401760).

261800 is an abundant number, since it is smaller than the sum of its proper divisors (541720).

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

261800 is a wasteful number, since it uses less digits than its factorization.

261800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51 (or 42 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 261800 is about 511.6639522186. The cubic root of 261800 is about 63.9719929540.

261800 divided by its sum of digits (17) gives a triangular number (15400 = T₁₇₅).

Adding to 261800 its reverse (8162), we get a palindrome (269962).

The spelling of 261800 in words is "two hundred sixty-one thousand, eight hundred".