121605102166 has 4 divisors (see below), whose sum is σ = 182407653252. Its totient is φ = 60802551082.

The previous prime is 121605102139. The next prime is 121605102169. The reversal of 121605102166 is 661201506121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 661201506121 = 13 ⋅50861654317.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121605102169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30401275540 + ... + 30401275543.

It is an arithmetic number, because the mean of its divisors is an integer number (45601913313).

Almost surely, 2^121605102166 is an apocalyptic number.

121605102166 is a deficient number, since it is larger than the sum of its proper divisors (60802551086).

121605102166 is an equidigital number, since it uses as much as digits as its factorization.

121605102166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60802551085.

The product of its (nonzero) digits is 4320, while the sum is 31.

Adding to 121605102166 its reverse (661201506121), we get a palindrome (782806608287).

The spelling of 121605102166 in words is "one hundred twenty-one billion, six hundred five million, one hundred two thousand, one hundred sixty-six".