1212020009 has 2 divisors, whose sum is σ = 1212020010. Its totient is φ = 1212020008.

The previous prime is 1212019993. The next prime is 1212020011. The reversal of 1212020009 is 9000202121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 994014784 + 218005225 = 31528^2 + 14765^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212020009 - 2⁴ = 1212019993 is a prime.

Together with 1212020011, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1212020039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606010004 + 606010005.

It is an arithmetic number, because the mean of its divisors is an integer number (606010005).

Almost surely, 2^1212020009 is an apocalyptic number.

It is an amenable number.

1212020009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212020009 is an equidigital number, since it uses as much as digits as its factorization.

1212020009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 1212020009 is about 34814.0777416263. The cubic root of 1212020009 is about 1066.1948894907.

The spelling of 1212020009 in words is "one billion, two hundred twelve million, twenty thousand, nine".