1212509509 has 2 divisors, whose sum is σ = 1212509510. Its totient is φ = 1212509508.

The previous prime is 1212509503. The next prime is 1212509521. The reversal of 1212509509 is 9059052121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 682358884 + 530150625 = 26122^2 + 23025^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212509509 - 2²³ = 1204120901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1212509503) 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, 606254754 + 606254755.

It is an arithmetic number, because the mean of its divisors is an integer number (606254755).

Almost surely, 2^1212509509 is an apocalyptic number.

It is an amenable number.

1212509509 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212509509 is an equidigital number, since it uses as much as digits as its factorization.

1212509509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8100, while the sum is 34.

The square root of 1212509509 is about 34821.1072339752. The cubic root of 1212509509 is about 1066.3384053155.

The spelling of 1212509509 in words is "one billion, two hundred twelve million, five hundred nine thousand, five hundred nine".