20643816049 has 8 divisors (see below), whose sum is σ = 20836684800. Its totient is φ = 20451671856.

The previous prime is 20643816047. The next prime is 20643816071. The reversal of 20643816049 is 94061834602.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20643816049 - 2¹ = 20643816047 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20643815996 and 20643816014.

It is not an unprimeable number, because it can be changed into a prime (20643816041) 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 7 ways as a sum of consecutive naturals, for example, 123807 + ... + 237940.

It is an arithmetic number, because the mean of its divisors is an integer number (2604585600).

Almost surely, 2^20643816049 is an apocalyptic number.

It is an amenable number.

20643816049 is a deficient number, since it is larger than the sum of its proper divisors (192868751).

20643816049 is a wasteful number, since it uses less digits than its factorization.

20643816049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362279.

The product of its (nonzero) digits is 248832, while the sum is 43.

The spelling of 20643816049 in words is "twenty billion, six hundred forty-three million, eight hundred sixteen thousand, forty-nine".