20669606816 has 12 divisors (see below), whose sum is σ = 40693288482. Its totient is φ = 10334803392.

The previous prime is 20669606801. The next prime is 20669606849. The reversal of 20669606816 is 61860696602.

It can be written as a sum of positive squares in only one way, i.e., 16026547216 + 4643059600 = 126596^2 + 68140^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322962575 + ... + 322962638.

Almost surely, 2^20669606816 is an apocalyptic number.

It is an amenable number.

20669606816 is a deficient number, since it is larger than the sum of its proper divisors (20023681666).

20669606816 is an equidigital number, since it uses as much as digits as its factorization.

20669606816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645925223 (or 645925215 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 50.

The spelling of 20669606816 in words is "twenty billion, six hundred sixty-nine million, six hundred six thousand, eight hundred sixteen".