19558505409 has 24 divisors (see below), whose sum is σ = 27636509472. Its totient is φ = 12296538240.

The previous prime is 19558505387. The next prime is 19558505429. The reversal of 19558505409 is 90450585591.

It is not a de Polignac number, because 19558505409 - 2²⁰ = 19557456833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19558505429) 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 in 23 ways as a sum of consecutive naturals, for example, 18349 + ... + 198629.

It is an arithmetic number, because the mean of its divisors is an integer number (1151521228).

Almost surely, 2^19558505409 is an apocalyptic number.

It is an amenable number.

19558505409 is a deficient number, since it is larger than the sum of its proper divisors (8078004063).

19558505409 is a wasteful number, since it uses less digits than its factorization.

19558505409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180385 (or 180356 counting only the distinct ones).

The product of its (nonzero) digits is 1620000, while the sum is 51.

The spelling of 19558505409 in words is "nineteen billion, five hundred fifty-eight million, five hundred five thousand, four hundred nine".