20809858403 has 4 divisors (see below), whose sum is σ = 20915492400. Its totient is φ = 20704224408.

The previous prime is 20809858393. The next prime is 20809858417. The reversal of 20809858403 is 30485890802.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20809858403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20809858463) 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, 52816703 + ... + 52817096.

It is an arithmetic number, because the mean of its divisors is an integer number (5228873100).

Almost surely, 2^20809858403 is an apocalyptic number.

20809858403 is a deficient number, since it is larger than the sum of its proper divisors (105633997).

20809858403 is a wasteful number, since it uses less digits than its factorization.

20809858403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105633996.

The product of its (nonzero) digits is 552960, while the sum is 47.

The spelling of 20809858403 in words is "twenty billion, eight hundred nine million, eight hundred fifty-eight thousand, four hundred three".