261072 has 90 divisors (see below), whose sum is σ = 872898. Its totient is φ = 72576.

The previous prime is 261071. The next prime is 261077. The reversal of 261072 is 270162.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 254016 + 7056 = 504^2 + 84^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

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 261072.

It is not an unprimeable number, because it can be changed into a prime (261071) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 7038 + ... + 7074.

2²⁶¹⁰⁷² is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (436449).

261072 is an abundant number, since it is smaller than the sum of its proper divisors (611826).

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

261072 is a wasteful number, since it uses less digits than its factorization.

261072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65 (or 49 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 261072 is about 510.9520525451. The cubic root of 261072 is about 63.9126412279.

It can be divided in two parts, 26 and 1072, that multiplied together give a palindrome (27872).

The spelling of 261072 in words is "two hundred sixty-one thousand, seventy-two".