121421125205 has 16 divisors (see below), whose sum is σ = 147874848240. Its totient is φ = 95693695488.

The previous prime is 121421125181. The next prime is 121421125213. The reversal of 121421125205 is 502521124121.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 48223281604 + 73197843601 = 219598^2 + 270551^2 .

It is a cyclic number.

It is not a de Polignac number, because 121421125205 - 2²⁰ = 121420076629 is a prime.

It is a congruent 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 15 ways as a sum of consecutive naturals, for example, 116351 + ... + 506339.

It is an arithmetic number, because the mean of its divisors is an integer number (9242178015).

Almost surely, 2^121421125205 is an apocalyptic number.

It is an amenable number.

121421125205 is a deficient number, since it is larger than the sum of its proper divisors (26453723035).

121421125205 is an equidigital number, since it uses as much as digits as its factorization.

121421125205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390920.

The product of its (nonzero) digits is 1600, while the sum is 26.

Adding to 121421125205 its reverse (502521124121), we get a palindrome (623942249326).

The spelling of 121421125205 in words is "one hundred twenty-one billion, four hundred twenty-one million, one hundred twenty-five thousand, two hundred five".