261600 has 72 divisors (see below), whose sum is σ = 859320. Its totient is φ = 69120.

The previous prime is 261593. The next prime is 261601. The reversal of 261600 is 6162.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 261600.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 261600.

It is not an unprimeable number, because it can be changed into a prime (261601) by changing a digit.

261600 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2346 + ... + 2454.

It is an arithmetic number, because the mean of its divisors is an integer number (11935).

2²⁶¹⁶⁰⁰ is an apocalyptic number.

261600 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 261600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (429660).

261600 is an abundant number, since it is smaller than the sum of its proper divisors (597720).

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

261600 is a wasteful number, since it uses less digits than its factorization.

261600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 261600 is about 511.4684741018. The cubic root of 261600 is about 63.9556985078.

Adding to 261600 its reverse (6162), we get a palindrome (267762).

It can be divided in two parts, 261 and 600, that added together give a triangular number (861 = T₄₁).

The spelling of 261600 in words is "two hundred sixty-one thousand, six hundred".