20678666687 has 4 divisors (see below), whose sum is σ = 23632761936. Its totient is φ = 17724571440.

The previous prime is 20678666639. The next prime is 20678666753. The reversal of 20678666687 is 78666687602.

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

It is a cyclic number.

It is not a de Polignac number, because 20678666687 - 2⁶ = 20678666623 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20678686687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1477047614 + ... + 1477047627.

It is an arithmetic number, because the mean of its divisors is an integer number (5908190484).

Almost surely, 2^20678666687 is an apocalyptic number.

20678666687 is a deficient number, since it is larger than the sum of its proper divisors (2954095249).

20678666687 is an equidigital number, since it uses as much as digits as its factorization.

20678666687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2954095248.

The product of its (nonzero) digits is 48771072, while the sum is 62.

The spelling of 20678666687 in words is "twenty billion, six hundred seventy-eight million, six hundred sixty-six thousand, six hundred eighty-seven".