121021009987 has 2 divisors, whose sum is σ = 121021009988. Its totient is φ = 121021009986.

The previous prime is 121021009961. The next prime is 121021010003. The reversal of 121021009987 is 789900120121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 121021009987 - 2¹⁵ = 121020977219 is a prime.

It is not a weakly prime, because it can be changed into another prime (121021009937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60510504993 + 60510504994.

It is an arithmetic number, because the mean of its divisors is an integer number (60510504994).

Almost surely, 2^121021009987 is an apocalyptic number.

121021009987 is a deficient number, since it is larger than the sum of its proper divisors (1).

121021009987 is an equidigital number, since it uses as much as digits as its factorization.

121021009987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 40.

The spelling of 121021009987 in words is "one hundred twenty-one billion, twenty-one million, nine thousand, nine hundred eighty-seven".