17981849 has 2 divisors, whose sum is σ = 17981850. Its totient is φ = 17981848.

The previous prime is 17981833. The next prime is 17981851. The reversal of 17981849 is 94818971.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13542400 + 4439449 = 3680^2 + 2107^2 .

It is a cyclic number.

It is not a de Polignac number, because 17981849 - 2⁴ = 17981833 is a prime.

Together with 17981851, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (17981819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8990924 + 8990925.

It is an arithmetic number, because the mean of its divisors is an integer number (8990925).

Almost surely, 2^17981849 is an apocalyptic number.

It is an amenable number.

17981849 is a deficient number, since it is larger than the sum of its proper divisors (1).

17981849 is an equidigital number, since it uses as much as digits as its factorization.

17981849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 47.

The square root of 17981849 is about 4240.5010317178. The cubic root of 17981849 is about 261.9860189109.

It can be divided in two parts, 179 and 81849, that added together give a palindrome (82028).

The spelling of 17981849 in words is "seventeen million, nine hundred eighty-one thousand, eight hundred forty-nine".