261213 has 4 divisors (see below), whose sum is σ = 348288. Its totient is φ = 174140.

The previous prime is 261169. The next prime is 261223. The reversal of 261213 is 312162.

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.

It is a cyclic number.

It is not a de Polignac number, because 261213 - 2¹⁰ = 260189 is a prime.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 261192 and 261201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43533 + ... + 43538.

It is an arithmetic number, because the mean of its divisors is an integer number (87072).

2²⁶¹²¹³ is an apocalyptic number.

It is an amenable number.

261213 is a deficient number, since it is larger than the sum of its proper divisors (87075).

261213 is an equidigital number, since it uses as much as digits as its factorization.

261213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87074.

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

The square root of 261213 is about 511.0900116418. The cubic root of 261213 is about 63.9241451560.

Adding to 261213 its reverse (312162), we get a palindrome (573375).

It can be divided in two parts, 261 and 213, that added together give a palindrome (474).

The spelling of 261213 in words is "two hundred sixty-one thousand, two hundred thirteen".