1999863 has 16 divisors (see below), whose sum is σ = 3137760. Its totient is φ = 1254528.

The previous prime is 1999859. The next prime is 1999867. The reversal of 1999863 is 3689991.

It is an interprime number because it is at equal distance from previous prime (1999859) and next prime (1999867).

It is not a de Polignac number, because 1999863 - 2² = 1999859 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999867) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1720 + ... + 2637.

It is an arithmetic number, because the mean of its divisors is an integer number (196110).

2^1999863 is an apocalyptic number.

1999863 is a deficient number, since it is larger than the sum of its proper divisors (1137897).

1999863 is a wasteful number, since it uses less digits than its factorization.

1999863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4383 (or 4377 counting only the distinct ones).

The product of its digits is 104976, while the sum is 45.

The square root of 1999863 is about 1414.1651247291. The cubic root of 1999863 is about 125.9892281041.

The spelling of 1999863 in words is "one million, nine hundred ninety-nine thousand, eight hundred sixty-three".