261766949 has 2 divisors, whose sum is σ = 261766950. Its totient is φ = 261766948.

The previous prime is 261766907. The next prime is 261766957. The reversal of 261766949 is 949667162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 211498849 + 50268100 = 14543^2 + 7090^2 .

It is a cyclic number.

It is not a de Polignac number, because 261766949 - 2¹⁶ = 261701413 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 261766897 and 261766906.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261766849) 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, 130883474 + 130883475.

It is an arithmetic number, because the mean of its divisors is an integer number (130883475).

Almost surely, 2^261766949 is an apocalyptic number.

It is an amenable number.

261766949 is a deficient number, since it is larger than the sum of its proper divisors (1).

261766949 is an equidigital number, since it uses as much as digits as its factorization.

261766949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 979776, while the sum is 50.

The square root of 261766949 is about 16179.2134852100. The cubic root of 261766949 is about 639.6930078777.

The spelling of 261766949 in words is "two hundred sixty-one million, seven hundred sixty-six thousand, nine hundred forty-nine".