261330 has 32 divisors (see below), whose sum is σ = 649728. Its totient is φ = 67200.

The previous prime is 261329. The next prime is 261337. The reversal of 261330 is 33162.

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

It is a Curzon number.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (261337) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 790 + ... + 1070.

It is an arithmetic number, because the mean of its divisors is an integer number (20304).

2²⁶¹³³⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324864).

261330 is an abundant number, since it is smaller than the sum of its proper divisors (388398).

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

261330 is a wasteful number, since it uses less digits than its factorization.

261330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322.

The product of its (nonzero) digits is 108, while the sum is 15.

The square root of 261330 is about 511.2044600744. The cubic root of 261330 is about 63.9336878263.

Adding to 261330 its reverse (33162), we get a palindrome (294492).

The spelling of 261330 in words is "two hundred sixty-one thousand, three hundred thirty".