121221209999 has 2 divisors, whose sum is σ = 121221210000. Its totient is φ = 121221209998.

The previous prime is 121221209983. The next prime is 121221210017. The reversal of 121221209999 is 999902122121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 121221209999 - 2⁴ = 121221209983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121221209969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610604999 + 60610605000.

It is an arithmetic number, because the mean of its divisors is an integer number (60610605000).

Almost surely, 2^121221209999 is an apocalyptic number.

121221209999 is a deficient number, since it is larger than the sum of its proper divisors (1).

121221209999 is an equidigital number, since it uses as much as digits as its factorization.

121221209999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 104976, while the sum is 47.

The spelling of 121221209999 in words is "one hundred twenty-one billion, two hundred twenty-one million, two hundred nine thousand, nine hundred ninety-nine".