121799999 has 2 divisors, whose sum is σ = 121800000. Its totient is φ = 121799998.

The previous prime is 121799969. The next prime is 121800017. The reversal of 121799999 is 999997121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 121799999 - 2¹² = 121795903 is a prime.

It is a Sophie Germain prime.

121799999 is a modest number, since divided by 99999 gives 1217 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121799929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60899999 + 60900000.

It is an arithmetic number, because the mean of its divisors is an integer number (60900000).

Almost surely, 2^121799999 is an apocalyptic number.

121799999 is a deficient number, since it is larger than the sum of its proper divisors (1).

121799999 is an equidigital number, since it uses as much as digits as its factorization.

121799999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 826686, while the sum is 56.

The square root of 121799999 is about 11036.3036837521. The cubic root of 121799999 is about 495.6963962659.

The spelling of 121799999 in words is "one hundred twenty-one million, seven hundred ninety-nine thousand, nine hundred ninety-nine".