1291663783 has 2 divisors, whose sum is σ = 1291663784. Its totient is φ = 1291663782.

The previous prime is 1291663771. The next prime is 1291663817. The reversal of 1291663783 is 3873661921.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1291663783 - 2⁹ = 1291663271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1291663883) 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, 645831891 + 645831892.

It is an arithmetic number, because the mean of its divisors is an integer number (645831892).

Almost surely, 2^1291663783 is an apocalyptic number.

1291663783 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291663783 is an equidigital number, since it uses as much as digits as its factorization.

1291663783 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 46.

The square root of 1291663783 is about 35939.7243033388. The cubic root of 1291663783 is about 1089.0550357357.

The spelling of 1291663783 in words is "one billion, two hundred ninety-one million, six hundred sixty-three thousand, seven hundred eighty-three".