261891141 has 32 divisors (see below), whose sum is σ = 370137600. Its totient is φ = 164472000.

The previous prime is 261891121. The next prime is 261891163. The reversal of 261891141 is 141198162.

It is not a de Polignac number, because 261891141 - 2⁵ = 261891109 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261891101) 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 31 ways as a sum of consecutive naturals, for example, 1043266 + ... + 1043516.

It is an arithmetic number, because the mean of its divisors is an integer number (11566800).

Almost surely, 2^261891141 is an apocalyptic number.

It is an amenable number.

261891141 is a deficient number, since it is larger than the sum of its proper divisors (108246459).

261891141 is a wasteful number, since it uses less digits than its factorization.

261891141 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 529.

The product of its digits is 3456, while the sum is 33.

The square root of 261891141 is about 16183.0510411356. The cubic root of 261891141 is about 639.7941566206.

The spelling of 261891141 in words is "two hundred sixty-one million, eight hundred ninety-one thousand, one hundred forty-one".