121866380173 has 2 divisors, whose sum is σ = 121866380174. Its totient is φ = 121866380172.

The previous prime is 121866380161. The next prime is 121866380179. The reversal of 121866380173 is 371083668121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84330417609 + 37535962564 = 290397^2 + 193742^2 .

It is a cyclic number.

It is not a de Polignac number, because 121866380173 - 2²⁹ = 121329509261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121866380179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60933190086 + 60933190087.

It is an arithmetic number, because the mean of its divisors is an integer number (60933190087).

Almost surely, 2^121866380173 is an apocalyptic number.

It is an amenable number.

121866380173 is a deficient number, since it is larger than the sum of its proper divisors (1).

121866380173 is an equidigital number, since it uses as much as digits as its factorization.

121866380173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 290304, while the sum is 46.

The spelling of 121866380173 in words is "one hundred twenty-one billion, eight hundred sixty-six million, three hundred eighty thousand, one hundred seventy-three".