1216358609 has 8 divisors (see below), whose sum is σ = 1264287360. Its totient is φ = 1169222256.

The previous prime is 1216358597. The next prime is 1216358617. The reversal of 1216358609 is 9068536121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1216358609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216358659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 194969 + ... + 201110.

It is an arithmetic number, because the mean of its divisors is an integer number (158035920).

Almost surely, 2^1216358609 is an apocalyptic number.

It is an amenable number.

1216358609 is a deficient number, since it is larger than the sum of its proper divisors (47928751).

1216358609 is an equidigital number, since it uses as much as digits as its factorization.

1216358609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396199.

The product of its (nonzero) digits is 77760, while the sum is 41.

The square root of 1216358609 is about 34876.3330784645. Note that the first 3 decimals coincide. The cubic root of 1216358609 is about 1067.4655738303.

The spelling of 1216358609 in words is "one billion, two hundred sixteen million, three hundred fifty-eight thousand, six hundred nine".