19663 has 6 divisors (see below), whose sum is σ = 22904. Its totient is φ = 16536.

The previous prime is 19661. The next prime is 19681. The reversal of 19663 is 36691.

It is not a de Polignac number, because 19663 - 2¹ = 19661 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19661) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 345 + ... + 397.

2¹⁹⁶⁶³ is an apocalyptic number.

19663 is a deficient number, since it is larger than the sum of its proper divisors (3241).

19663 is an frugal number, since it uses more digits than its factorization.

19663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113 (or 60 counting only the distinct ones).

The product of its digits is 972, while the sum is 25.

The square root of 19663 is about 140.2248194864. The cubic root of 19663 is about 26.9908519534.

The spelling of 19663 in words is "nineteen thousand, six hundred sixty-three".