20664810718 has 4 divisors (see below), whose sum is σ = 30997216080. Its totient is φ = 10332405358.

The previous prime is 20664810679. The next prime is 20664810721. The reversal of 20664810718 is 81701846602.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5166202678 + ... + 5166202681.

It is an arithmetic number, because the mean of its divisors is an integer number (7749304020).

Almost surely, 2^20664810718 is an apocalyptic number.

20664810718 is a deficient number, since it is larger than the sum of its proper divisors (10332405362).

20664810718 is a wasteful number, since it uses less digits than its factorization.

20664810718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10332405361.

The product of its (nonzero) digits is 129024, while the sum is 43.

The spelling of 20664810718 in words is "twenty billion, six hundred sixty-four million, eight hundred ten thousand, seven hundred eighteen".