20663717 has 4 divisors (see below), whose sum is σ = 20772096. Its totient is φ = 20555340.

The previous prime is 20663707. The next prime is 20663719. The reversal of 20663717 is 71736602.

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.

It is a cyclic number.

It is not a de Polignac number, because 20663717 - 2¹⁰ = 20662693 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 (20663719) 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, 53903 + ... + 54284.

It is an arithmetic number, because the mean of its divisors is an integer number (5193024).

Almost surely, 2^20663717 is an apocalyptic number.

It is an amenable number.

20663717 is a deficient number, since it is larger than the sum of its proper divisors (108379).

20663717 is a wasteful number, since it uses less digits than its factorization.

20663717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108378.

The product of its (nonzero) digits is 10584, while the sum is 32.

The square root of 20663717 is about 4545.7361340051. The cubic root of 20663717 is about 274.4118205645.

The spelling of 20663717 in words is "twenty million, six hundred sixty-three thousand, seven hundred seventeen".