1200121009 has 2 divisors, whose sum is σ = 1200121010. Its totient is φ = 1200121008.

The previous prime is 1200120989. The next prime is 1200121019. The reversal of 1200121009 is 9001210021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 820650609 + 379470400 = 28647^2 + 19480^2 .

It is an emirp because it is prime and its reverse (9001210021) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1200121009 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1200120983 and 1200121001.

It is not a weakly prime, because it can be changed into another prime (1200121019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600060504 + 600060505.

It is an arithmetic number, because the mean of its divisors is an integer number (600060505).

Almost surely, 2^1200121009 is an apocalyptic number.

It is an amenable number.

1200121009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1200121009 is an equidigital number, since it uses as much as digits as its factorization.

1200121009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 1200121009 is about 34642.7627218154. The cubic root of 1200121009 is about 1062.6942877739.

The spelling of 1200121009 in words is "one billion, two hundred million, one hundred twenty-one thousand, nine".