20717663 has 2 divisors, whose sum is σ = 20717664. Its totient is φ = 20717662.

The previous prime is 20717651. The next prime is 20717677. The reversal of 20717663 is 36671702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20717663 - 2¹⁰ = 20716639 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20717603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10358831 + 10358832.

It is an arithmetic number, because the mean of its divisors is an integer number (10358832).

Almost surely, 2^20717663 is an apocalyptic number.

20717663 is a deficient number, since it is larger than the sum of its proper divisors (1).

20717663 is an equidigital number, since it uses as much as digits as its factorization.

20717663 is an evil number, because the sum of its binary digits is even.

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

The square root of 20717663 is about 4551.6659587452. The cubic root of 20717663 is about 274.6504119802.

The spelling of 20717663 in words is "twenty million, seven hundred seventeen thousand, six hundred sixty-three".