261848689 has 2 divisors, whose sum is σ = 261848690. Its totient is φ = 261848688.

The previous prime is 261848683. The next prime is 261848729. The reversal of 261848689 is 986848162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 169208064 + 92640625 = 13008^2 + 9625^2 .

It is a cyclic number.

It is not a de Polignac number, because 261848689 - 2³ = 261848681 is a prime.

It is not a weakly prime, because it can be changed into another prime (261848681) 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 as a sum of consecutive naturals, namely, 130924344 + 130924345.

It is an arithmetic number, because the mean of its divisors is an integer number (130924345).

Almost surely, 2^261848689 is an apocalyptic number.

It is an amenable number.

261848689 is a deficient number, since it is larger than the sum of its proper divisors (1).

261848689 is an equidigital number, since it uses as much as digits as its factorization.

261848689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1327104, while the sum is 52.

The square root of 261848689 is about 16181.7393688071. The cubic root of 261848689 is about 639.7595849928.

The spelling of 261848689 in words is "two hundred sixty-one million, eight hundred forty-eight thousand, six hundred eighty-nine".