1291768209 has 8 divisors (see below), whose sum is σ = 1913730720. Its totient is φ = 861178788.

The previous prime is 1291768207. The next prime is 1291768223. The reversal of 1291768209 is 9028671921.

It is not a de Polignac number, because 1291768209 - 2¹ = 1291768207 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1291768207) 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 in 7 ways as a sum of consecutive naturals, for example, 23921607 + ... + 23921660.

It is an arithmetic number, because the mean of its divisors is an integer number (239216340).

Almost surely, 2^1291768209 is an apocalyptic number.

It is an amenable number.

1291768209 is a deficient number, since it is larger than the sum of its proper divisors (621962511).

1291768209 is an equidigital number, since it uses as much as digits as its factorization.

1291768209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47843276 (or 47843270 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The square root of 1291768209 is about 35941.1770675363. The cubic root of 1291768209 is about 1089.0843835681.

The spelling of 1291768209 in words is "one billion, two hundred ninety-one million, seven hundred sixty-eight thousand, two hundred nine".