1618020209 has 4 divisors (see below), whose sum is σ = 1742483316. Its totient is φ = 1493557104.

The previous prime is 1618020197. The next prime is 1618020233. The reversal of 1618020209 is 9020208161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 984390625 + 633629584 = 31375^2 + 25172^2 .

It is not a de Polignac number, because 1618020209 - 2⁴ = 1618020193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1618020289) 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 in 3 ways as a sum of consecutive naturals, for example, 62231534 + ... + 62231559.

It is an arithmetic number, because the mean of its divisors is an integer number (435620829).

Almost surely, 2^1618020209 is an apocalyptic number.

It is an amenable number.

1618020209 is a deficient number, since it is larger than the sum of its proper divisors (124463107).

1618020209 is a wasteful number, since it uses less digits than its factorization.

1618020209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124463106.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 1618020209 is about 40224.6219248858. The cubic root of 1618020209 is about 1173.9816640053.

The spelling of 1618020209 in words is "one billion, six hundred eighteen million, twenty thousand, two hundred nine".