261166949 has 2 divisors, whose sum is σ = 261166950. Its totient is φ = 261166948.

The previous prime is 261166931. The next prime is 261166963. The reversal of 261166949 is 949661162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 236236900 + 24930049 = 15370^2 + 4993^2 .

It is a cyclic number.

It is not a de Polignac number, because 261166949 - 2⁸ = 261166693 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 (261166999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130583474 + 130583475.

It is an arithmetic number, because the mean of its divisors is an integer number (130583475).

Almost surely, 2^261166949 is an apocalyptic number.

It is an amenable number.

261166949 is a deficient number, since it is larger than the sum of its proper divisors (1).

261166949 is an equidigital number, since it uses as much as digits as its factorization.

261166949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 139968, while the sum is 44.

The square root of 261166949 is about 16160.6605372429. The cubic root of 261166949 is about 639.2038839576.

The spelling of 261166949 in words is "two hundred sixty-one million, one hundred sixty-six thousand, nine hundred forty-nine".