1205415509 has 2 divisors, whose sum is σ = 1205415510. Its totient is φ = 1205415508.

The previous prime is 1205415503. The next prime is 1205415529. The reversal of 1205415509 is 9055145021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 814246225 + 391169284 = 28535^2 + 19778^2 .

It is a cyclic number.

It is not a de Polignac number, because 1205415509 - 2¹² = 1205411413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1205415503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 602707754 + 602707755.

It is an arithmetic number, because the mean of its divisors is an integer number (602707755).

Almost surely, 2^1205415509 is an apocalyptic number.

It is an amenable number.

1205415509 is a deficient number, since it is larger than the sum of its proper divisors (1).

1205415509 is an equidigital number, since it uses as much as digits as its factorization.

1205415509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9000, while the sum is 32.

The square root of 1205415509 is about 34719.0942998230. The cubic root of 1205415509 is about 1064.2547363041.

The spelling of 1205415509 in words is "one billion, two hundred five million, four hundred fifteen thousand, five hundred nine".