261334511 has 4 divisors (see below), whose sum is σ = 261446832. Its totient is φ = 261222192.

The previous prime is 261334501. The next prime is 261334517. The reversal of 261334511 is 115433162.

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 261334511 - 2¹⁰ = 261333487 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261334517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52595 + ... + 57348.

It is an arithmetic number, because the mean of its divisors is an integer number (65361708).

Almost surely, 2^261334511 is an apocalyptic number.

261334511 is a deficient number, since it is larger than the sum of its proper divisors (112321).

261334511 is a wasteful number, since it uses less digits than its factorization.

261334511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112320.

The product of its digits is 2160, while the sum is 26.

The square root of 261334511 is about 16165.8439618846. The cubic root of 261334511 is about 639.3405569219.

Adding to 261334511 its reverse (115433162), we get a palindrome (376767673).

The spelling of 261334511 in words is "two hundred sixty-one million, three hundred thirty-four thousand, five hundred eleven".