1291864759649 has 2 divisors, whose sum is σ = 1291864759650. Its totient is φ = 1291864759648.

The previous prime is 1291864759643. The next prime is 1291864759693. The reversal of 1291864759649 is 9469574681921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1231345315600 + 60519444049 = 1109660^2 + 246007^2 .

It is a cyclic number.

It is not a de Polignac number, because 1291864759649 - 2¹² = 1291864755553 is a prime.

It is not a weakly prime, because it can be changed into another prime (1291864759643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645932379824 + 645932379825.

It is an arithmetic number, because the mean of its divisors is an integer number (645932379825).

Almost surely, 2^{1291864759649} is an apocalyptic number.

It is an amenable number.

1291864759649 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291864759649 is an equidigital number, since it uses as much as digits as its factorization.

1291864759649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 235146240, while the sum is 71.

The spelling of 1291864759649 in words is "one trillion, two hundred ninety-one billion, eight hundred sixty-four million, seven hundred fifty-nine thousand, six hundred forty-nine".