19948009 has 2 divisors, whose sum is σ = 19948010. Its totient is φ = 19948008.

The previous prime is 19947997. The next prime is 19948013. The reversal of 19948009 is 90084991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19669225 + 278784 = 4435^2 + 528^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19948009 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19948909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9974004 + 9974005.

It is an arithmetic number, because the mean of its divisors is an integer number (9974005).

Almost surely, 2^19948009 is an apocalyptic number.

It is an amenable number.

19948009 is a deficient number, since it is larger than the sum of its proper divisors (1).

19948009 is an equidigital number, since it uses as much as digits as its factorization.

19948009 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 40.

The square root of 19948009 is about 4466.3194019237. The cubic root of 19948009 is about 271.2063487418.

The spelling of 19948009 in words is "nineteen million, nine hundred forty-eight thousand, nine".