121220021999 has 2 divisors, whose sum is σ = 121220022000. Its totient is φ = 121220021998.

The previous prime is 121220021987. The next prime is 121220022067. The reversal of 121220021999 is 999120022121.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 121220021999 - 2³² = 116925054703 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121220021929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610010999 + 60610011000.

It is an arithmetic number, because the mean of its divisors is an integer number (60610011000).

Almost surely, 2^121220021999 is an apocalyptic number.

121220021999 is a deficient number, since it is larger than the sum of its proper divisors (1).

121220021999 is an equidigital number, since it uses as much as digits as its factorization.

121220021999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 38.

The spelling of 121220021999 in words is "one hundred twenty-one billion, two hundred twenty million, twenty-one thousand, nine hundred ninety-nine".