20815577966 has 4 divisors (see below), whose sum is σ = 31223366952. Its totient is φ = 10407788982.

The previous prime is 20815577917. The next prime is 20815577969. The reversal of 20815577966 is 66977551802.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20815577969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5203894490 + ... + 5203894493.

It is an arithmetic number, because the mean of its divisors is an integer number (7805841738).

Almost surely, 2^20815577966 is an apocalyptic number.

20815577966 is a deficient number, since it is larger than the sum of its proper divisors (10407788986).

20815577966 is a wasteful number, since it uses less digits than its factorization.

20815577966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10407788985.

The product of its (nonzero) digits is 6350400, while the sum is 56.

The spelling of 20815577966 in words is "twenty billion, eight hundred fifteen million, five hundred seventy-seven thousand, nine hundred sixty-six".