19890859 has 2 divisors, whose sum is σ = 19890860. Its totient is φ = 19890858.

The previous prime is 19890841. The next prime is 19890881. The reversal of 19890859 is 95809891.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19890859 - 2⁹ = 19890347 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19897859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9945429 + 9945430.

It is an arithmetic number, because the mean of its divisors is an integer number (9945430).

Almost surely, 2^19890859 is an apocalyptic number.

19890859 is a deficient number, since it is larger than the sum of its proper divisors (1).

19890859 is an equidigital number, since it uses as much as digits as its factorization.

19890859 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 233280, while the sum is 49.

The square root of 19890859 is about 4459.9169274775. The cubic root of 19890859 is about 270.9471036858.

The spelling of 19890859 in words is "nineteen million, eight hundred ninety thousand, eight hundred fifty-nine".