12121210205 has 32 divisors (see below), whose sum is σ = 16597786464. Its totient is φ = 8418410496.

The previous prime is 12121210177. The next prime is 12121210207. The reversal of 12121210205 is 50201212121.

It can be written as a sum of positive squares in 16 ways, for example, as 6907936996 + 5213273209 = 83114^2 + 72203^2 .

It is a cyclic number.

It is not a de Polignac number, because 12121210205 - 2²⁰ = 12120161629 is a prime.

It is a super-2 number, since 2×12121210205² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121210207) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1960499 + ... + 1966671.

It is an arithmetic number, because the mean of its divisors is an integer number (518680827).

Almost surely, 2^12121210205 is an apocalyptic number.

It is an amenable number.

12121210205 is a deficient number, since it is larger than the sum of its proper divisors (4476576259).

12121210205 is a wasteful number, since it uses less digits than its factorization.

12121210205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7985.

The product of its (nonzero) digits is 80, while the sum is 17.

Adding to 12121210205 its reverse (50201212121), we get a palindrome (62322422326).

The spelling of 12121210205 in words is "twelve billion, one hundred twenty-one million, two hundred ten thousand, two hundred five".