181984009 has 2 divisors, whose sum is σ = 181984010. Its totient is φ = 181984008.

The previous prime is 181984003. The next prime is 181984039. The reversal of 181984009 is 900489181.

181984009 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 178142409 + 3841600 = 13347^2 + 1960^2 .

It is an emirp because it is prime and its reverse (900489181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 181984009 - 2³ = 181984001 is a prime.

It is not a weakly prime, because it can be changed into another prime (181984001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90992004 + 90992005.

It is an arithmetic number, because the mean of its divisors is an integer number (90992005).

Almost surely, 2^181984009 is an apocalyptic number.

It is an amenable number.

181984009 is a deficient number, since it is larger than the sum of its proper divisors (1).

181984009 is an equidigital number, since it uses as much as digits as its factorization.

181984009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 181984009 is about 13490.1448843220. The cubic root of 181984009 is about 566.6885129217.

The spelling of 181984009 in words is "one hundred eighty-one million, nine hundred eighty-four thousand, nine".