20863577809 has 4 divisors (see below), whose sum is σ = 21536596480. Its totient is φ = 20190559140.

The previous prime is 20863577789. The next prime is 20863577827. The reversal of 20863577809 is 90877536802.

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 a de Polignac number, because none of the positive numbers 2^k-20863577809 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20863577809.

It is not an unprimeable number, because it can be changed into a prime (20863577849) 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, 336509289 + ... + 336509350.

It is an arithmetic number, because the mean of its divisors is an integer number (5384149120).

Almost surely, 2^20863577809 is an apocalyptic number.

It is an amenable number.

20863577809 is a deficient number, since it is larger than the sum of its proper divisors (673018671).

20863577809 is an equidigital number, since it uses as much as digits as its factorization.

20863577809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 673018670.

The product of its (nonzero) digits is 5080320, while the sum is 55.

The spelling of 20863577809 in words is "twenty billion, eight hundred sixty-three million, five hundred seventy-seven thousand, eight hundred nine".