2181983549 has 4 divisors (see below), whose sum is σ = 2182522560. Its totient is φ = 2181444540.

The previous prime is 2181983537. The next prime is 2181983563. The reversal of 2181983549 is 9453891812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2181983549 - 2²⁴ = 2165206333 is a prime.

It is a super-2 number, since 2×2181983549² = 9522104416213270802, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2181983497 and 2181983506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181983149) 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, 263387 + ... + 271544.

It is an arithmetic number, because the mean of its divisors is an integer number (545630640).

Almost surely, 2^2181983549 is an apocalyptic number.

It is an amenable number.

2181983549 is a deficient number, since it is larger than the sum of its proper divisors (539011).

2181983549 is an equidigital number, since it uses as much as digits as its factorization.

2181983549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539010.

The product of its digits is 622080, while the sum is 50.

The square root of 2181983549 is about 46711.7067660774. The cubic root of 2181983549 is about 1297.0314016002.

The spelling of 2181983549 in words is "two billion, one hundred eighty-one million, nine hundred eighty-three thousand, five hundred forty-nine".