3261 has 4 divisors (see below), whose sum is σ = 4352. Its totient is φ = 2172.

The previous prime is 3259. The next prime is 3271. The reversal of 3261 is 1623.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1623 = 3 ⋅541.

It is not a de Polignac number, because 3261 - 2¹ = 3259 is a prime.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

3261 is a lucky number.

It is a plaindrome in base 7 and base 14.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 541 + ... + 546.

It is an arithmetic number, because the mean of its divisors is an integer number (1088).

2³²⁶¹ is an apocalyptic number.

It is an amenable number.

3261 is a deficient number, since it is larger than the sum of its proper divisors (1091).

3261 is a wasteful number, since it uses less digits than its factorization.

3261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1090.

The product of its digits is 36, while the sum is 12.

The square root of 3261 is about 57.1051661411. The cubic root of 3261 is about 14.8291730397.

Subtracting from 3261 its sum of digits (12), we obtain a square (3249 = 57²).

Adding to 3261 its reverse (1623), we get a palindrome (4884).

The spelling of 3261 in words is "three thousand, two hundred sixty-one".