1243255124557 has 2 divisors, whose sum is σ = 1243255124558. Its totient is φ = 1243255124556.

The previous prime is 1243255124533. The next prime is 1243255124569. The reversal of 1243255124557 is 7554215523421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1149728640516 + 93526484041 = 1072254^2 + 305821^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243255124557 - 2⁷ = 1243255124429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1243255124057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621627562278 + 621627562279.

It is an arithmetic number, because the mean of its divisors is an integer number (621627562279).

Almost surely, 2^{1243255124557} is an apocalyptic number.

It is an amenable number.

1243255124557 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243255124557 is an equidigital number, since it uses as much as digits as its factorization.

1243255124557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1680000, while the sum is 46.

The spelling of 1243255124557 in words is "one trillion, two hundred forty-three billion, two hundred fifty-five million, one hundred twenty-four thousand, five hundred fifty-seven".