20679663 has 4 divisors (see below), whose sum is σ = 27572888. Its totient is φ = 13786440.

The previous prime is 20679653. The next prime is 20679679. The reversal of 20679663 is 36697602.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20679663 - 2⁹ = 20679151 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 (20679613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3446608 + ... + 3446613.

It is an arithmetic number, because the mean of its divisors is an integer number (6893222).

Almost surely, 2^20679663 is an apocalyptic number.

20679663 is a deficient number, since it is larger than the sum of its proper divisors (6893225).

20679663 is an equidigital number, since it uses as much as digits as its factorization.

20679663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6893224.

The product of its (nonzero) digits is 81648, while the sum is 39.

The square root of 20679663 is about 4547.4897471022. The cubic root of 20679663 is about 274.4823894396.

The spelling of 20679663 in words is "twenty million, six hundred seventy-nine thousand, six hundred sixty-three".