1281602394557 has 2 divisors, whose sum is σ = 1281602394558. Its totient is φ = 1281602394556.

The previous prime is 1281602394547. The next prime is 1281602394607. The reversal of 1281602394557 is 7554932061821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1098400418116 + 183201976441 = 1048046^2 + 428021^2 .

It is a cyclic number.

It is not a de Polignac number, because 1281602394557 - 2⁸ = 1281602394301 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1281602394499 and 1281602394508.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1281602394517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640801197278 + 640801197279.

It is an arithmetic number, because the mean of its divisors is an integer number (640801197279).

It is a 2-persistent number, because it is pandigital, and so is 2⋅1281602394557 = 2563204789114, but 3⋅1281602394557 = 3844807183671 is not.

Almost surely, 2^{1281602394557} is an apocalyptic number.

It is an amenable number.

1281602394557 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281602394557 is an equidigital number, since it uses as much as digits as its factorization.

1281602394557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3628800, while the sum is 53.

The spelling of 1281602394557 in words is "one trillion, two hundred eighty-one billion, six hundred two million, three hundred ninety-four thousand, five hundred fifty-seven".