1816552109 has 4 divisors (see below), whose sum is σ = 1860858300. Its totient is φ = 1772245920.

The previous prime is 1816552103. The next prime is 1816552151. The reversal of 1816552109 is 9012556181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9012556181 = 71 ⋅126937411.

It can be written as a sum of positive squares in 2 ways, for example, as 538704100 + 1277848009 = 23210^2 + 35747^2 .

It is a cyclic number.

It is not a de Polignac number, because 1816552109 - 2⁴ = 1816552093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1816552103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22153034 + ... + 22153115.

It is an arithmetic number, because the mean of its divisors is an integer number (465214575).

Almost surely, 2^1816552109 is an apocalyptic number.

It is an amenable number.

1816552109 is a deficient number, since it is larger than the sum of its proper divisors (44306191).

1816552109 is an equidigital number, since it uses as much as digits as its factorization.

1816552109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44306190.

The product of its (nonzero) digits is 21600, while the sum is 38.

The square root of 1816552109 is about 42621.0289528538. The cubic root of 1816552109 is about 1220.1576677443.

The spelling of 1816552109 in words is "one billion, eight hundred sixteen million, five hundred fifty-two thousand, one hundred nine".