1989863 has 2 divisors, whose sum is σ = 1989864. Its totient is φ = 1989862.

The previous prime is 1989847. The next prime is 1989877. The reversal of 1989863 is 3689891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1989863 - 2⁴ = 1989847 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1989803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994931 + 994932.

It is an arithmetic number, because the mean of its divisors is an integer number (994932).

2^1989863 is an apocalyptic number.

1989863 is a deficient number, since it is larger than the sum of its proper divisors (1).

1989863 is an equidigital number, since it uses as much as digits as its factorization.

1989863 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 44.

The square root of 1989863 is about 1410.6250387683. The cubic root of 1989863 is about 125.7788806789.

The spelling of 1989863 in words is "one million, nine hundred eighty-nine thousand, eight hundred sixty-three".