261040011 has 4 divisors (see below), whose sum is σ = 348053352. Its totient is φ = 174026672.

The previous prime is 261040001. The next prime is 261040019. The reversal of 261040011 is 110040162.

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 261040011 - 2²⁵ = 227485579 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261040019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43506666 + ... + 43506671.

It is an arithmetic number, because the mean of its divisors is an integer number (87013338).

Almost surely, 2^261040011 is an apocalyptic number.

261040011 is a deficient number, since it is larger than the sum of its proper divisors (87013341).

261040011 is an equidigital number, since it uses as much as digits as its factorization.

261040011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87013340.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 261040011 is about 16156.7326833119. The cubic root of 261040011 is about 639.1003072836.

Adding to 261040011 its reverse (110040162), we get a palindrome (371080173).

The spelling of 261040011 in words is "two hundred sixty-one million, forty thousand, eleven".