261887 has 2 divisors, whose sum is σ = 261888. Its totient is φ = 261886.

The previous prime is 261881. The next prime is 261917. The reversal of 261887 is 788162.

261887 is nontrivially palindromic in base 4.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261887 - 2⁶ = 261823 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261881) 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 as a sum of consecutive naturals, namely, 130943 + 130944.

It is an arithmetic number, because the mean of its divisors is an integer number (130944).

261887 is a Friedman number, since it can be written as 8^6-2^8-1^7, using all its digits and the basic arithmetic operations.

2²⁶¹⁸⁸⁷ is an apocalyptic number.

261887 is a deficient number, since it is larger than the sum of its proper divisors (1).

261887 is an equidigital number, since it uses as much as digits as its factorization.

261887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5376, while the sum is 32.

The square root of 261887 is about 511.7489618944. The cubic root of 261887 is about 63.9790784480.

The spelling of 261887 in words is "two hundred sixty-one thousand, eight hundred eighty-seven".