19999103 has 4 divisors (see below), whose sum is σ = 20486928. Its totient is φ = 19511280.

The previous prime is 19999069. The next prime is 19999117. The reversal of 19999103 is 30199991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19999103 - 2¹⁶ = 19933567 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 487783 = 19999103 / (1 + 9 + 9 + 9 + 9 + 1 + 0 + 3).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19999193) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 243851 + ... + 243932.

It is an arithmetic number, because the mean of its divisors is an integer number (5121732).

Almost surely, 2^19999103 is an apocalyptic number.

19999103 is a deficient number, since it is larger than the sum of its proper divisors (487825).

19999103 is an equidigital number, since it uses as much as digits as its factorization.

19999103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487824.

The product of its (nonzero) digits is 19683, while the sum is 41.

The square root of 19999103 is about 4472.0356662263. The cubic root of 19999103 is about 271.4377035445.

It can be divided in two parts, 19999 and 103, that added together give a palindrome (20102).

The spelling of 19999103 in words is "nineteen million, nine hundred ninety-nine thousand, one hundred three".