261343291 has 4 divisors (see below), whose sum is σ = 285101784. Its totient is φ = 237584800.

The previous prime is 261343259. The next prime is 261343301. The reversal of 261343291 is 192343162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261343291 - 2⁵ = 261343259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261343211) 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, 11879230 + ... + 11879251.

It is an arithmetic number, because the mean of its divisors is an integer number (71275446).

Almost surely, 2^261343291 is an apocalyptic number.

261343291 is a deficient number, since it is larger than the sum of its proper divisors (23758493).

261343291 is a wasteful number, since it uses less digits than its factorization.

261343291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23758492.

The product of its digits is 7776, while the sum is 31.

The square root of 261343291 is about 16166.1155198149. The cubic root of 261343291 is about 639.3477167713.

The spelling of 261343291 in words is "two hundred sixty-one million, three hundred forty-three thousand, two hundred ninety-one".