12187678121 has 2 divisors, whose sum is σ = 12187678122. Its totient is φ = 12187678120.

The previous prime is 12187678099. The next prime is 12187678189.

12187678121 is nontrivially palindromic in base 10.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9841632025 + 2346046096 = 99205^2 + 48436^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 12187678121 - 2¹⁴ = 12187661737 is a prime.

It is a super-2 number, since 2×12187678121² (a number of 21 digits) contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (12187671121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6093839060 + 6093839061.

It is an arithmetic number, because the mean of its divisors is an integer number (6093839061).

Almost surely, 2^12187678121 is an apocalyptic number.

It is an amenable number.

12187678121 is a deficient number, since it is larger than the sum of its proper divisors (1).

12187678121 is an equidigital number, since it uses as much as digits as its factorization.

12187678121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75264, while the sum is 44.

The spelling of 12187678121 in words is "twelve billion, one hundred eighty-seven million, six hundred seventy-eight thousand, one hundred twenty-one".