291261 has 8 divisors (see below), whose sum is σ = 411264. Its totient is φ = 182720.

The previous prime is 291257. The next prime is 291271. The reversal of 291261 is 162192.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 291261 - 2² = 291257 is a prime.

291261 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (291271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2805 + ... + 2906.

It is an arithmetic number, because the mean of its divisors is an integer number (51408).

2²⁹¹²⁶¹ is an apocalyptic number.

It is an amenable number.

291261 is a deficient number, since it is larger than the sum of its proper divisors (120003).

291261 is a wasteful number, since it uses less digits than its factorization.

291261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5731.

The product of its digits is 216, while the sum is 21.

The square root of 291261 is about 539.6860198300. The cubic root of 291261 is about 66.2868597542.

The spelling of 291261 in words is "two hundred ninety-one thousand, two hundred sixty-one".