18400049 has 2 divisors, whose sum is σ = 18400050. Its totient is φ = 18400048.

The previous prime is 18400013. The next prime is 18400051. The reversal of 18400049 is 94000481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12673600 + 5726449 = 3560^2 + 2393^2 .

It is an emirp because it is prime and its reverse (94000481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18400049 - 2²⁴ = 1622833 is a prime.

Together with 18400051, 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 (18490049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9200024 + 9200025.

It is an arithmetic number, because the mean of its divisors is an integer number (9200025).

Almost surely, 2^18400049 is an apocalyptic number.

It is an amenable number.

18400049 is a deficient number, since it is larger than the sum of its proper divisors (1).

18400049 is an equidigital number, since it uses as much as digits as its factorization.

18400049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 18400049 is about 4289.5278294936. The cubic root of 18400049 is about 264.0014587079.

The spelling of 18400049 in words is "eighteen million, four hundred thousand, forty-nine".