20675641666 has 16 divisors (see below), whose sum is σ = 32415763968. Its totient is φ = 9871884000.

The previous prime is 20675641627. The next prime is 20675641667. The reversal of 20675641666 is 66614657602.

It is not an unprimeable number, because it can be changed into a prime (20675641667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 346290 + ... + 401581.

It is an arithmetic number, because the mean of its divisors is an integer number (2025985248).

Almost surely, 2^20675641666 is an apocalyptic number.

20675641666 is a deficient number, since it is larger than the sum of its proper divisors (11740122302).

20675641666 is a wasteful number, since it uses less digits than its factorization.

20675641666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 748497.

The product of its (nonzero) digits is 2177280, while the sum is 49.

The spelling of 20675641666 in words is "twenty billion, six hundred seventy-five million, six hundred forty-one thousand, six hundred sixty-six".