1278240531643 has 2 divisors, whose sum is σ = 1278240531644. Its totient is φ = 1278240531642.

The previous prime is 1278240531629. The next prime is 1278240531713. The reversal of 1278240531643 is 3461350428721.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1278240531643 - 2³³ = 1269650597051 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1278240531593 and 1278240531602.

It is not a weakly prime, because it can be changed into another prime (1278240531443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639120265821 + 639120265822.

It is an arithmetic number, because the mean of its divisors is an integer number (639120265822).

Almost surely, 2^{1278240531643} is an apocalyptic number.

1278240531643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278240531643 is an equidigital number, since it uses as much as digits as its factorization.

1278240531643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 967680, while the sum is 46.

The spelling of 1278240531643 in words is "one trillion, two hundred seventy-eight billion, two hundred forty million, five hundred thirty-one thousand, six hundred forty-three".