20405565905859 has 20 divisors (see below), whose sum is σ = 32275470258504. Its totient is φ = 12803492332224.

The previous prime is 20405565905839. The next prime is 20405565905863. The reversal of 20405565905859 is 95850956550402.

20405565905859 is a `hidden beast` number, since 2 + 0 + 40 + 5 + 5 + 6 + 5 + 9 + 0 + 585 + 9 = 666.

It is not a de Polignac number, because 20405565905859 - 2⁵ = 20405565905827 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20405565905796 and 20405565905805.

It is not an unprimeable number, because it can be changed into a prime (20405565905839) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 7409427057 + ... + 7409429810.

Almost surely, 2^{20405565905859} is an apocalyptic number.

20405565905859 is a deficient number, since it is larger than the sum of its proper divisors (11869904352645).

20405565905859 is a wasteful number, since it uses less digits than its factorization.

20405565905859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14818856896 (or 14818856887 counting only the distinct ones).

The product of its (nonzero) digits is 97200000, while the sum is 63.

The spelling of 20405565905859 in words is "twenty trillion, four hundred five billion, five hundred sixty-five million, nine hundred five thousand, eight hundred fifty-nine".