63998009 has 2 divisors, whose sum is σ = 63998010. Its totient is φ = 63998008.

The previous prime is 63998003. The next prime is 63998027. The reversal of 63998009 is 90089936.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52417600 + 11580409 = 7240^2 + 3403^2 .

It is a cyclic number.

It is not a de Polignac number, because 63998009 - 2⁴ = 63997993 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (63998003) 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, 31999004 + 31999005.

It is an arithmetic number, because the mean of its divisors is an integer number (31999005).

Almost surely, 2^63998009 is an apocalyptic number.

It is an amenable number.

63998009 is a deficient number, since it is larger than the sum of its proper divisors (1).

63998009 is an equidigital number, since it uses as much as digits as its factorization.

63998009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104976, while the sum is 44.

The square root of 63998009 is about 7999.8755615322. The cubic root of 63998009 is about 399.9958520403.

The spelling of 63998009 in words is "sixty-three million, nine hundred ninety-eight thousand, nine".