20666880677 has 4 divisors (see below), whose sum is σ = 20793671520. Its totient is φ = 20540089836.

The previous prime is 20666880673. The next prime is 20666880683. The reversal of 20666880677 is 77608866602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20666880677 - 2² = 20666880673 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20666880673) 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, 63395177 + ... + 63395502.

It is an arithmetic number, because the mean of its divisors is an integer number (5198417880).

Almost surely, 2^20666880677 is an apocalyptic number.

It is an amenable number.

20666880677 is a deficient number, since it is larger than the sum of its proper divisors (126790843).

20666880677 is a wasteful number, since it uses less digits than its factorization.

20666880677 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126790842.

The product of its (nonzero) digits is 8128512, while the sum is 56.

The spelling of 20666880677 in words is "twenty billion, six hundred sixty-six million, eight hundred eighty thousand, six hundred seventy-seven".