1291396069 has 2 divisors, whose sum is σ = 1291396070. Its totient is φ = 1291396068.

The previous prime is 1291396063. The next prime is 1291396097. The reversal of 1291396069 is 9606931921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1286083044 + 5313025 = 35862^2 + 2305^2 .

It is an emirp because it is prime and its reverse (9606931921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1291396069 - 2⁹ = 1291395557 is a prime.

It is a super-2 number, since 2×1291396069² = 3335407614057305522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1291396063) 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, 645698034 + 645698035.

It is an arithmetic number, because the mean of its divisors is an integer number (645698035).

Almost surely, 2^1291396069 is an apocalyptic number.

It is an amenable number.

1291396069 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291396069 is an equidigital number, since it uses as much as digits as its factorization.

1291396069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 157464, while the sum is 46.

The square root of 1291396069 is about 35935.9996243321. Note that the first 3 decimals coincide. The cubic root of 1291396069 is about 1088.9797902968.

The spelling of 1291396069 in words is "one billion, two hundred ninety-one million, three hundred ninety-six thousand, sixty-nine".