19803989 has 4 divisors (see below), whose sum is σ = 20665056. Its totient is φ = 18942924.

The previous prime is 19803983. The next prime is 19804003. The reversal of 19803989 is 98930891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98930891 = 19 ⋅5206889.

It is a cyclic number.

It is not a de Polignac number, because 19803989 - 2⁸ = 19803733 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19803983) 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, 430499 + ... + 430544.

It is an arithmetic number, because the mean of its divisors is an integer number (5166264).

Almost surely, 2^19803989 is an apocalyptic number.

It is an amenable number.

19803989 is a deficient number, since it is larger than the sum of its proper divisors (861067).

19803989 is an equidigital number, since it uses as much as digits as its factorization.

19803989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 861066.

The product of its (nonzero) digits is 139968, while the sum is 47.

The square root of 19803989 is about 4450.1673002259. The cubic root of 19803989 is about 270.5520893533.

The spelling of 19803989 in words is "nineteen million, eight hundred three thousand, nine hundred eighty-nine".