121369321161 has 243 divisors, whose sum is σ = 222205282663. Its totient is φ = 66220260480.

The previous prime is 121369321111. The next prime is 121369321219. The reversal of 121369321161 is 161123963121.

The square root of 121369321161 is 348381.

It is a perfect power (a square), and thus also a powerful number.

121369321161 is a `hidden beast` number, since 1 + 21 + 369 + 3 + 211 + 61 = 666.

It can be written as a sum of positive squares in only one way, i.e., 94491686025 + 26877635136 = 307395^2 + 163944^2 .

It is a tau number, because it is divible by the number of its divisors (243).

It is not a de Polignac number, because 121369321161 - 2⁷ = 121369321033 is a prime.

It is a Duffinian number.

Its product of digits (11664) is a multiple of the sum of its prime divisors (54).

It is not an unprimeable number, because it can be changed into a prime (121369321111) by changing a digit.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 5276926996 + ... + 5276927018.

Almost surely, 2^121369321161 is an apocalyptic number.

121369321161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

121369321161 is the 348381-st square number.

121369321161 is the 174191-st centered octagonal number.

It is an amenable number.

121369321161 is a deficient number, since it is larger than the sum of its proper divisors (100835961502).

121369321161 is an frugal number, since it uses more digits than its factorization.

121369321161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126 (or 54 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

Multiplying 121369321161 by its sum of digits (36), we get a square (4369295561796 = 2090286²).

The spelling of 121369321161 in words is "one hundred twenty-one billion, three hundred sixty-nine million, three hundred twenty-one thousand, one hundred sixty-one".