20646663 has 16 divisors (see below), whose sum is σ = 29126400. Its totient is φ = 12982464.

The previous prime is 20646631. The next prime is 20646667. The reversal of 20646663 is 36664602.

It is not a de Polignac number, because 20646663 - 2⁵ = 20646631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20646667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2988 + ... + 7086.

It is an arithmetic number, because the mean of its divisors is an integer number (1820400).

Almost surely, 2^20646663 is an apocalyptic number.

20646663 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

20646663 is a deficient number, since it is larger than the sum of its proper divisors (8479737).

20646663 is a wasteful number, since it uses less digits than its factorization.

20646663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4198.

The product of its (nonzero) digits is 31104, while the sum is 33.

The square root of 20646663 is about 4543.8599230170. The cubic root of 20646663 is about 274.3363080576.

The spelling of 20646663 in words is "twenty million, six hundred forty-six thousand, six hundred sixty-three".