1275243673661 has 2 divisors, whose sum is σ = 1275243673662. Its totient is φ = 1275243673660.

The previous prime is 1275243673601. The next prime is 1275243673681. The reversal of 1275243673661 is 1663763425721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 852841168036 + 422402505625 = 923494^2 + 649925^2 .

It is an emirp because it is prime and its reverse (1663763425721) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1275243673661 - 2³⁴ = 1258063804477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1275243673601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 637621836830 + 637621836831.

It is an arithmetic number, because the mean of its divisors is an integer number (637621836831).

Almost surely, 2^{1275243673661} is an apocalyptic number.

It is an amenable number.

1275243673661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1275243673661 is an equidigital number, since it uses as much as digits as its factorization.

1275243673661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7620480, while the sum is 53.

The spelling of 1275243673661 in words is "one trillion, two hundred seventy-five billion, two hundred forty-three million, six hundred seventy-three thousand, six hundred sixty-one".