19981863 has 32 divisors (see below), whose sum is σ = 34003200. Its totient is φ = 11469600.

The previous prime is 19981807. The next prime is 19981867. The reversal of 19981863 is 36818991.

It is not a de Polignac number, because 19981863 - 2¹⁸ = 19719719 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19981867) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3873 + ... + 7413.

It is an arithmetic number, because the mean of its divisors is an integer number (1062600).

Almost surely, 2^19981863 is an apocalyptic number.

19981863 is a deficient number, since it is larger than the sum of its proper divisors (14021337).

19981863 is a wasteful number, since it uses less digits than its factorization.

19981863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3580 (or 3574 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 19981863 is about 4470.1077168229. The cubic root of 19981863 is about 271.3596845234.

The spelling of 19981863 in words is "nineteen million, nine hundred eighty-one thousand, eight hundred sixty-three".