121124205155 has 4 divisors (see below), whose sum is σ = 145349046192. Its totient is φ = 96899364120.

The previous prime is 121124205121. The next prime is 121124205263. The reversal of 121124205155 is 551502421121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 551502421121 = 191 ⋅2887447231.

It is not a de Polignac number, because 121124205155 - 2⁸ = 121124204899 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 12112420511 + ... + 12112420520.

It is an arithmetic number, because the mean of its divisors is an integer number (36337261548).

Almost surely, 2^121124205155 is an apocalyptic number.

121124205155 is a deficient number, since it is larger than the sum of its proper divisors (24224841037).

121124205155 is an equidigital number, since it uses as much as digits as its factorization.

121124205155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24224841036.

The product of its (nonzero) digits is 4000, while the sum is 29.

Adding to 121124205155 its reverse (551502421121), we get a palindrome (672626626276).

The spelling of 121124205155 in words is "one hundred twenty-one billion, one hundred twenty-four million, two hundred five thousand, one hundred fifty-five".