121512215121 has 16 divisors (see below), whose sum is σ = 177059001600. Its totient is φ = 73512949520.

The previous prime is 121512215119. The next prime is 121512215129.

121512215121 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 121512215121 - 2¹ = 121512215119 is a prime.

It is a super-2 number, since 2×121512215121² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 121512215091 and 121512215100.

It is not an unprimeable number, because it can be changed into a prime (121512215129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3251571 + ... + 3288728.

It is an arithmetic number, because the mean of its divisors is an integer number (11066187600).

Almost surely, 2^121512215121 is an apocalyptic number.

121512215121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121512215121 is a deficient number, since it is larger than the sum of its proper divisors (55546786479).

121512215121 is a wasteful number, since it uses less digits than its factorization.

121512215121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6540876.

The product of its digits is 400, while the sum is 24.

It can be divided in two parts, 121512 and 215121, that added together give a palindrome (336633).

The spelling of 121512215121 in words is "one hundred twenty-one billion, five hundred twelve million, two hundred fifteen thousand, one hundred twenty-one".