12121987 has 2 divisors, whose sum is σ = 12121988. Its totient is φ = 12121986.

The previous prime is 12121979. The next prime is 12122009. The reversal of 12121987 is 78912121.

It is a weak prime.

It is an emirp because it is prime and its reverse (78912121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12121987 - 2³ = 12121979 is a prime.

It is not a weakly prime, because it can be changed into another prime (12121927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6060993 + 6060994.

It is an arithmetic number, because the mean of its divisors is an integer number (6060994).

Almost surely, 2^12121987 is an apocalyptic number.

12121987 is a deficient number, since it is larger than the sum of its proper divisors (1).

12121987 is an equidigital number, since it uses as much as digits as its factorization.

12121987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 31.

The square root of 12121987 is about 3481.6644008290. The cubic root of 12121987 is about 229.7160137091.

The spelling of 12121987 in words is "twelve million, one hundred twenty-one thousand, nine hundred eighty-seven".