1211200009 has 2 divisors, whose sum is σ = 1211200010. Its totient is φ = 1211200008.

The previous prime is 1211199971. The next prime is 1211200031. The reversal of 1211200009 is 9000021121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1197160000 + 14040009 = 34600^2 + 3747^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211200009 - 2⁹ = 1211199497 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211199965 and 1211200001.

It is not a weakly prime, because it can be changed into another prime (1211209009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605600004 + 605600005.

It is an arithmetic number, because the mean of its divisors is an integer number (605600005).

Almost surely, 2^1211200009 is an apocalyptic number.

It is an amenable number.

1211200009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211200009 is an equidigital number, since it uses as much as digits as its factorization.

1211200009 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 1211200009 is about 34802.2989039517. The cubic root of 1211200009 is about 1065.9543882219.

The spelling of 1211200009 in words is "one billion, two hundred eleven million, two hundred thousand, nine".