121505305166021 has 12 divisors (see below), whose sum is σ = 141348459682188. Its totient is φ = 104143312248192.

The previous prime is 121505305165991. The next prime is 121505305166027. The reversal of 121505305166021 is 120661503505121.

It can be written as a sum of positive squares in 2 ways, for example, as 2910047044996 + 118595258121025 = 1705886^2 + 10890145^2 .

It is not a de Polignac number, because 121505305166021 - 2¹⁴ = 121505305149637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121505305166027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 47456306 + ... + 49951091.

It is an arithmetic number, because the mean of its divisors is an integer number (11779038306849).

Almost surely, 2^{121505305166021} is an apocalyptic number.

It is an amenable number.

121505305166021 is a deficient number, since it is larger than the sum of its proper divisors (19843154516167).

121505305166021 is an equidigital number, since it uses as much as digits as its factorization.

121505305166021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97432868 (or 97432861 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 38.

The spelling of 121505305166021 in words is "one hundred twenty-one trillion, five hundred five billion, three hundred five million, one hundred sixty-six thousand, twenty-one".