20656666508 has 12 divisors (see below), whose sum is σ = 37126171152. Its totient is φ = 10049189040.

The previous prime is 20656666501. The next prime is 20656666517. The reversal of 20656666508 is 80566665602.

It is not an unprimeable number, because it can be changed into a prime (20656666501) 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, 69785888 + ... + 69786183.

It is an arithmetic number, because the mean of its divisors is an integer number (3093847596).

Almost surely, 2^20656666508 is an apocalyptic number.

It is an amenable number.

20656666508 is a deficient number, since it is larger than the sum of its proper divisors (16469504644).

20656666508 is a wasteful number, since it uses less digits than its factorization.

20656666508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139572112 (or 139572110 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 50.

The spelling of 20656666508 in words is "twenty billion, six hundred fifty-six million, six hundred sixty-six thousand, five hundred eight".