1818398609 has 2 divisors, whose sum is σ = 1818398610. Its totient is φ = 1818398608.

The previous prime is 1818398509. The next prime is 1818398641. The reversal of 1818398609 is 9068938181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1816890625 + 1507984 = 42625^2 + 1228^2 .

It is a cyclic number.

It is not a de Polignac number, because 1818398609 - 2²⁰ = 1817350033 is a prime.

It is not a weakly prime, because it can be changed into another prime (1818398669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 909199304 + 909199305.

It is an arithmetic number, because the mean of its divisors is an integer number (909199305).

Almost surely, 2^1818398609 is an apocalyptic number.

It is an amenable number.

1818398609 is a deficient number, since it is larger than the sum of its proper divisors (1).

1818398609 is an equidigital number, since it uses as much as digits as its factorization.

1818398609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 746496, while the sum is 53.

The square root of 1818398609 is about 42642.6852930253. The cubic root of 1818398609 is about 1220.5709521866.

The spelling of 1818398609 in words is "one billion, eight hundred eighteen million, three hundred ninety-eight thousand, six hundred nine".