261261 has 48 divisors (see below), whose sum is σ = 524160. Its totient is φ = 120960.

The previous prime is 261251. The next prime is 261271. The reversal of 261261 is 162162.

It is a happy number.

261261 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (261251) and next prime (261271).

261261 is an admirable number.

It is not a de Polignac number, because 261261 - 2⁵ = 261229 is a prime.

261261 is strictly pandigital in base 7.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261241) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8995 + ... + 9023.

It is an arithmetic number, because the mean of its divisors is an integer number (10920).

2²⁶¹²⁶¹ is an apocalyptic number.

261261 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

261261 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.

261261 is a wasteful number, since it uses less digits than its factorization.

261261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66 (or 63 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 261261 is about 511.1369679450. The cubic root of 261261 is about 63.9280604423.

Subtracting from 261261 its reverse (162162), we obtain a palindrome (99099).

The spelling of 261261 in words is "two hundred sixty-one thousand, two hundred sixty-one".