12121517121 has 64 divisors (see below), whose sum is σ = 19750072320. Its totient is φ = 6466118400.

The previous prime is 12121517071. The next prime is 12121517141. The reversal of 12121517121 is 12171512121.

It is a de Polignac number, because none of the positive numbers 2^k-12121517121 is a prime.

It is a super-2 number, since 2×12121517121² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 12121517091 and 12121517100.

It is not an unprimeable number, because it can be changed into a prime (12121517141) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2642596 + ... + 2647178.

It is an arithmetic number, because the mean of its divisors is an integer number (308594880).

Almost surely, 2^12121517121 is an apocalyptic number.

It is an amenable number.

12121517121 is a deficient number, since it is larger than the sum of its proper divisors (7628555199).

12121517121 is a wasteful number, since it uses less digits than its factorization.

12121517121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4766.

The product of its digits is 280, while the sum is 24.

Subtracting 12121517121 from its reverse (12171512121), we obtain a triangular number (49995000 = T₉₉₉₉).

The spelling of 12121517121 in words is "twelve billion, one hundred twenty-one million, five hundred seventeen thousand, one hundred twenty-one".