1298793721921 has 2 divisors, whose sum is σ = 1298793721922. Its totient is φ = 1298793721920.

The previous prime is 1298793721891. The next prime is 1298793721993. The reversal of 1298793721921 is 1291273978921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1246882656321 + 51911065600 = 1116639^2 + 227840^2 .

It is a cyclic number.

It is not a de Polignac number, because 1298793721921 - 2¹³ = 1298793713729 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1298793721921.

It is not a weakly prime, because it can be changed into another prime (1298793721021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 649396860960 + 649396860961.

It is an arithmetic number, because the mean of its divisors is an integer number (649396860961).

Almost surely, 2^{1298793721921} is an apocalyptic number.

It is an amenable number.

1298793721921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1298793721921 is an equidigital number, since it uses as much as digits as its factorization.

1298793721921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6858432, while the sum is 61.

The spelling of 1298793721921 in words is "one trillion, two hundred ninety-eight billion, seven hundred ninety-three million, seven hundred twenty-one thousand, nine hundred twenty-one".