1819213009 has 4 divisors (see below), whose sum is σ = 1863584100. Its totient is φ = 1774841920.

The previous prime is 1819213001. The next prime is 1819213013. The reversal of 1819213009 is 9003129181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9003129181 = 18257 ⋅493133.

It can be written as a sum of positive squares in 2 ways, for example, as 395811025 + 1423401984 = 19895^2 + 37728^2 .

It is a cyclic number.

It is not a de Polignac number, because 1819213009 - 2³ = 1819213001 is a prime.

It is a super-2 number, since 2×1819213009² = 6619071944229668162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1819213001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22185484 + ... + 22185565.

It is an arithmetic number, because the mean of its divisors is an integer number (465896025).

Almost surely, 2^1819213009 is an apocalyptic number.

It is an amenable number.

1819213009 is a deficient number, since it is larger than the sum of its proper divisors (44371091).

1819213009 is an equidigital number, since it uses as much as digits as its factorization.

1819213009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44371090.

The product of its (nonzero) digits is 3888, while the sum is 34.

The square root of 1819213009 is about 42652.2333412918. The cubic root of 1819213009 is about 1220.7531426439.

The spelling of 1819213009 in words is "one billion, eight hundred nineteen million, two hundred thirteen thousand, nine".