19998403 has 2 divisors, whose sum is σ = 19998404. Its totient is φ = 19998402.

The previous prime is 19998383. The next prime is 19998413. The reversal of 19998403 is 30489991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19998403 - 2²¹ = 17901251 is a prime.

It is a super-2 number, since 2×19998403² = 799872245100818, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19998403.

It is not a weakly prime, because it can be changed into another prime (19998413) 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, 9999201 + 9999202.

It is an arithmetic number, because the mean of its divisors is an integer number (9999202).

Almost surely, 2^19998403 is an apocalyptic number.

19998403 is a deficient number, since it is larger than the sum of its proper divisors (1).

19998403 is an equidigital number, since it uses as much as digits as its factorization.

19998403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69984, while the sum is 43.

The square root of 19998403 is about 4471.9574014071. The cubic root of 19998403 is about 271.4345365923.

The spelling of 19998403 in words is "nineteen million, nine hundred ninety-eight thousand, four hundred three".