1220999495789 has 2 divisors, whose sum is σ = 1220999495790. Its totient is φ = 1220999495788.

The previous prime is 1220999495759. The next prime is 1220999495791. The reversal of 1220999495789 is 9875949990221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 876479802025 + 344519693764 = 936205^2 + 586958^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220999495789 - 2⁸ = 1220999495533 is a prime.

Together with 1220999495791, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220999495759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610499747894 + 610499747895.

It is an arithmetic number, because the mean of its divisors is an integer number (610499747895).

Almost surely, 2^{1220999495789} is an apocalyptic number.

It is an amenable number.

1220999495789 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220999495789 is an equidigital number, since it uses as much as digits as its factorization.

1220999495789 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 264539520, while the sum is 74.

The spelling of 1220999495789 in words is "one trillion, two hundred twenty billion, nine hundred ninety-nine million, four hundred ninety-five thousand, seven hundred eighty-nine".