19890019 has 2 divisors, whose sum is σ = 19890020. Its totient is φ = 19890018.

The previous prime is 19890007. The next prime is 19890029. The reversal of 19890019 is 91009891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19890019 - 2¹¹ = 19887971 is a prime.

It is a super-2 number, since 2×19890019² = 791225711640722, 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 19890019.

It is not a weakly prime, because it can be changed into another prime (19890029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9945009 + 9945010.

It is an arithmetic number, because the mean of its divisors is an integer number (9945010).

Almost surely, 2^19890019 is an apocalyptic number.

19890019 is a deficient number, since it is larger than the sum of its proper divisors (1).

19890019 is an equidigital number, since it uses as much as digits as its factorization.

19890019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 37.

The square root of 19890019 is about 4459.8227543256. The cubic root of 19890019 is about 270.9432895590.

The spelling of 19890019 in words is "nineteen million, eight hundred ninety thousand, nineteen".