19987903 has 16 divisors (see below), whose sum is σ = 22982400. Its totient is φ = 17220096.

The previous prime is 19987879. The next prime is 19987907. The reversal of 19987903 is 30978991.

It is a cyclic number.

It is not a de Polignac number, because 19987903 - 2¹³ = 19979711 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19987907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32626 + ... + 33232.

It is an arithmetic number, because the mean of its divisors is an integer number (1436400).

Almost surely, 2^19987903 is an apocalyptic number.

19987903 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

19987903 is a deficient number, since it is larger than the sum of its proper divisors (2994497).

19987903 is a wasteful number, since it uses less digits than its factorization.

19987903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 786.

The product of its (nonzero) digits is 122472, while the sum is 46.

The square root of 19987903 is about 4470.7832647088. The cubic root of 19987903 is about 271.3870234387.

The spelling of 19987903 in words is "nineteen million, nine hundred eighty-seven thousand, nine hundred three".