12121617121 has 4 divisors (see below), whose sum is σ = 12350326932. Its totient is φ = 11892907312.

The previous prime is 12121617103. The next prime is 12121617127. The reversal of 12121617121 is 12171612121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4176390625 + 7945226496 = 64625^2 + 89136^2 .

It is a cyclic number.

It is not a de Polignac number, because 12121617121 - 2¹³ = 12121608929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12121617127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114354826 + ... + 114354931.

It is an arithmetic number, because the mean of its divisors is an integer number (3087581733).

Almost surely, 2^12121617121 is an apocalyptic number.

It is an amenable number.

12121617121 is a deficient number, since it is larger than the sum of its proper divisors (228709811).

12121617121 is an equidigital number, since it uses as much as digits as its factorization.

12121617121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228709810.

The product of its digits is 336, while the sum is 25.

Subtracting 12121617121 from its reverse (12171612121), we obtain a triangular number (49995000 = T₉₉₉₉).

The spelling of 12121617121 in words is "twelve billion, one hundred twenty-one million, six hundred seventeen thousand, one hundred twenty-one".