121644785021 has 2 divisors, whose sum is σ = 121644785022. Its totient is φ = 121644785020.

The previous prime is 121644784969. The next prime is 121644785029. The reversal of 121644785021 is 120587446121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 112534082521 + 9110702500 = 335461^2 + 95450^2 .

It is a cyclic number.

It is not a de Polignac number, because 121644785021 - 2²² = 121640590717 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121644785021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121644785029) 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, 60822392510 + 60822392511.

It is an arithmetic number, because the mean of its divisors is an integer number (60822392511).

Almost surely, 2^121644785021 is an apocalyptic number.

It is an amenable number.

121644785021 is a deficient number, since it is larger than the sum of its proper divisors (1).

121644785021 is an equidigital number, since it uses as much as digits as its factorization.

121644785021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 107520, while the sum is 41.

The spelling of 121644785021 in words is "one hundred twenty-one billion, six hundred forty-four million, seven hundred eighty-five thousand, twenty-one".