1261017917 has 2 divisors, whose sum is σ = 1261017918. Its totient is φ = 1261017916.

The previous prime is 1261017899. The next prime is 1261017929. The reversal of 1261017917 is 7197101621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 874148356 + 386869561 = 29566^2 + 19669^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261017917 - 2¹⁰ = 1261016893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261017997) 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, 630508958 + 630508959.

It is an arithmetic number, because the mean of its divisors is an integer number (630508959).

Almost surely, 2^1261017917 is an apocalyptic number.

It is an amenable number.

1261017917 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261017917 is an equidigital number, since it uses as much as digits as its factorization.

1261017917 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5292, while the sum is 35.

The square root of 1261017917 is about 35510.8140852896. The cubic root of 1261017917 is about 1080.3730755565.

The spelling of 1261017917 in words is "one billion, two hundred sixty-one million, seventeen thousand, nine hundred seventeen".