121781456773 has 2 divisors, whose sum is σ = 121781456774. Its totient is φ = 121781456772.

The previous prime is 121781456749. The next prime is 121781456777. The reversal of 121781456773 is 377654187121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66266086084 + 55515370689 = 257422^2 + 235617^2 .

It is an emirp because it is prime and its reverse (377654187121) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121781456773 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121781456773.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121781456777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60890728386 + 60890728387.

It is an arithmetic number, because the mean of its divisors is an integer number (60890728387).

Almost surely, 2^121781456773 is an apocalyptic number.

It is an amenable number.

121781456773 is a deficient number, since it is larger than the sum of its proper divisors (1).

121781456773 is an equidigital number, since it uses as much as digits as its factorization.

121781456773 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1975680, while the sum is 52.

The spelling of 121781456773 in words is "one hundred twenty-one billion, seven hundred eighty-one million, four hundred fifty-six thousand, seven hundred seventy-three".