121755374021 has 2 divisors, whose sum is σ = 121755374022. Its totient is φ = 121755374020.

The previous prime is 121755373973. The next prime is 121755374047. The reversal of 121755374021 is 120473557121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 106474953025 + 15280420996 = 326305^2 + 123614^2 .

It is a cyclic number.

It is not a de Polignac number, because 121755374021 - 2²⁶ = 121688265157 is a prime.

It is a super-2 number, since 2×121755374021² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121755370021) 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, 60877687010 + 60877687011.

It is an arithmetic number, because the mean of its divisors is an integer number (60877687011).

Almost surely, 2^121755374021 is an apocalyptic number.

It is an amenable number.

121755374021 is a deficient number, since it is larger than the sum of its proper divisors (1).

121755374021 is an equidigital number, since it uses as much as digits as its factorization.

121755374021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 58800, while the sum is 38.

The spelling of 121755374021 in words is "one hundred twenty-one billion, seven hundred fifty-five million, three hundred seventy-four thousand, twenty-one".