1243087371857 has 2 divisors, whose sum is σ = 1243087371858. Its totient is φ = 1243087371856.

The previous prime is 1243087371833. The next prime is 1243087371859. The reversal of 1243087371857 is 7581737803421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1063818965056 + 179268406801 = 1031416^2 + 423401^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243087371857 - 2⁸ = 1243087371601 is a prime.

Together with 1243087371859, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1243087371859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621543685928 + 621543685929.

It is an arithmetic number, because the mean of its divisors is an integer number (621543685929).

Almost surely, 2^{1243087371857} is an apocalyptic number.

It is an amenable number.

1243087371857 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243087371857 is an equidigital number, since it uses as much as digits as its factorization.

1243087371857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7902720, while the sum is 56.

The spelling of 1243087371857 in words is "one trillion, two hundred forty-three billion, eighty-seven million, three hundred seventy-one thousand, eight hundred fifty-seven".