1289021787761 has 2 divisors, whose sum is σ = 1289021787762. Its totient is φ = 1289021787760.

The previous prime is 1289021787649. The next prime is 1289021787769. The reversal of 1289021787761 is 1677871209821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1166000434225 + 123021353536 = 1079815^2 + 350744^2 .

It is a cyclic number.

It is not a de Polignac number, because 1289021787761 - 2³⁴ = 1271841918577 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1289021787761.

It is not a weakly prime, because it can be changed into another prime (1289021787769) 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, 644510893880 + 644510893881.

It is an arithmetic number, because the mean of its divisors is an integer number (644510893881).

Almost surely, 2^{1289021787761} is an apocalyptic number.

It is an amenable number.

1289021787761 is a deficient number, since it is larger than the sum of its proper divisors (1).

1289021787761 is an equidigital number, since it uses as much as digits as its factorization.

1289021787761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4741632, while the sum is 59.

The spelling of 1289021787761 in words is "one trillion, two hundred eighty-nine billion, twenty-one million, seven hundred eighty-seven thousand, seven hundred sixty-one".