20663983 has 4 divisors (see below), whose sum is σ = 21014280. Its totient is φ = 20313688.

The previous prime is 20663977. The next prime is 20663987. The reversal of 20663983 is 38936602.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 38936602 = 2 ⋅19468301.

It is a cyclic number.

It is not a de Polignac number, because 20663983 - 2⁹ = 20663471 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 (20663987) 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, 175060 + ... + 175177.

It is an arithmetic number, because the mean of its divisors is an integer number (5253570).

Almost surely, 2^20663983 is an apocalyptic number.

20663983 is a deficient number, since it is larger than the sum of its proper divisors (350297).

20663983 is an equidigital number, since it uses as much as digits as its factorization.

20663983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350296.

The product of its (nonzero) digits is 46656, while the sum is 37.

The square root of 20663983 is about 4545.7653920985. The cubic root of 20663983 is about 274.4129980427.

The spelling of 20663983 in words is "twenty million, six hundred sixty-three thousand, nine hundred eighty-three".