20668783 has 4 divisors (see below), whose sum is σ = 20713888. Its totient is φ = 20623680.

The previous prime is 20668777. The next prime is 20668799. The reversal of 20668783 is 38786602.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20668783 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 (20668733) 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, 21858 + ... + 22783.

It is an arithmetic number, because the mean of its divisors is an integer number (5178472).

Almost surely, 2^20668783 is an apocalyptic number.

20668783 is a deficient number, since it is larger than the sum of its proper divisors (45105).

20668783 is an equidigital number, since it uses as much as digits as its factorization.

20668783 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45104.

The product of its (nonzero) digits is 96768, while the sum is 40.

The square root of 20668783 is about 4546.2933253366. The cubic root of 20668783 is about 274.4342440341.

The spelling of 20668783 in words is "twenty million, six hundred sixty-eight thousand, seven hundred eighty-three".