19918049 has 2 divisors, whose sum is σ = 19918050. Its totient is φ = 19918048.

The previous prime is 19918043. The next prime is 19918057. The reversal of 19918049 is 94081991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17977600 + 1940449 = 4240^2 + 1393^2 .

It is an emirp because it is prime and its reverse (94081991) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19918049 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 19917997 and 19918015.

It is not a weakly prime, because it can be changed into another prime (19918043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9959024 + 9959025.

It is an arithmetic number, because the mean of its divisors is an integer number (9959025).

Almost surely, 2^19918049 is an apocalyptic number.

It is an amenable number.

19918049 is a deficient number, since it is larger than the sum of its proper divisors (1).

19918049 is an equidigital number, since it uses as much as digits as its factorization.

19918049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 41.

The square root of 19918049 is about 4462.9641495311. The cubic root of 19918049 is about 271.0705053863.

The spelling of 19918049 in words is "nineteen million, nine hundred eighteen thousand, forty-nine".