2149985209 has 4 divisors (see below), whose sum is σ = 2224122660. Its totient is φ = 2075847760.

The previous prime is 2149985179. The next prime is 2149985239. The reversal of 2149985209 is 9025899412.

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

It is an interprime number because it is at equal distance from previous prime (2149985179) and next prime (2149985239).

It can be written as a sum of positive squares in 2 ways, for example, as 998876025 + 1151109184 = 31605^2 + 33928^2 .

It is a cyclic number.

It is not a de Polignac number, because 2149985209 - 2¹³ = 2149977017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2149985239) 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, 37068682 + ... + 37068739.

It is an arithmetic number, because the mean of its divisors is an integer number (556030665).

Almost surely, 2^2149985209 is an apocalyptic number.

2149985209 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

2149985209 is a deficient number, since it is larger than the sum of its proper divisors (74137451).

2149985209 is an equidigital number, since it uses as much as digits as its factorization.

2149985209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74137450.

The product of its (nonzero) digits is 466560, while the sum is 49.

The square root of 2149985209 is about 46367.9329817494. The cubic root of 2149985209 is about 1290.6599209471.

The spelling of 2149985209 in words is "two billion, one hundred forty-nine million, nine hundred eighty-five thousand, two hundred nine".