20807663 has 4 divisors (see below), whose sum is σ = 21712368. Its totient is φ = 19902960.

The previous prime is 20807629. The next prime is 20807687. The reversal of 20807663 is 36670802.

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

It is a cyclic number.

It is not a de Polignac number, because 20807663 - 2⁸ = 20807407 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20807693) 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, 452318 + ... + 452363.

It is an arithmetic number, because the mean of its divisors is an integer number (5428092).

Almost surely, 2^20807663 is an apocalyptic number.

20807663 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

20807663 is a deficient number, since it is larger than the sum of its proper divisors (904705).

20807663 is an equidigital number, since it uses as much as digits as its factorization.

20807663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 904704.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 20807663 is about 4561.5417349839. The cubic root of 20807663 is about 275.0475421936.

The spelling of 20807663 in words is "twenty million, eight hundred seven thousand, six hundred sixty-three".