121644785209 has 2 divisors, whose sum is σ = 121644785210. Its totient is φ = 121644785208.

The previous prime is 121644785051. The next prime is 121644785279. The reversal of 121644785209 is 902587446121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91690868025 + 29953917184 = 302805^2 + 173072^2 .

It is a cyclic number.

It is not a de Polignac number, because 121644785209 - 2¹³ = 121644777017 is a prime.

It is not a weakly prime, because it can be changed into another prime (121644785279) 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, 60822392604 + 60822392605.

It is an arithmetic number, because the mean of its divisors is an integer number (60822392605).

Almost surely, 2^121644785209 is an apocalyptic number.

It is an amenable number.

121644785209 is a deficient number, since it is larger than the sum of its proper divisors (1).

121644785209 is an equidigital number, since it uses as much as digits as its factorization.

121644785209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 967680, while the sum is 49.

The spelling of 121644785209 in words is "one hundred twenty-one billion, six hundred forty-four million, seven hundred eighty-five thousand, two hundred nine".