1306668691 has 2 divisors, whose sum is σ = 1306668692. Its totient is φ = 1306668690.

The previous prime is 1306668581. The next prime is 1306668721. The reversal of 1306668691 is 1968666031.

It is a strong prime.

It is an emirp because it is prime and its reverse (1968666031) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1306668691 - 2¹⁹ = 1306144403 is a prime.

It is not a weakly prime, because it can be changed into another prime (1306668191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 653334345 + 653334346.

It is an arithmetic number, because the mean of its divisors is an integer number (653334346).

Almost surely, 2^1306668691 is an apocalyptic number.

1306668691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1306668691 is an equidigital number, since it uses as much as digits as its factorization.

1306668691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 279936, while the sum is 46.

The square root of 1306668691 is about 36147.8725653392. The cubic root of 1306668691 is about 1093.2558964361.

The spelling of 1306668691 in words is "one billion, three hundred six million, six hundred sixty-eight thousand, six hundred ninety-one".