19805018780089 has 3 divisors (see below), whose sum is σ = 19805023230373. Its totient is φ = 19805014329806.

The previous prime is 19805018780039. The next prime is 19805018780161. The reversal of 19805018780089 is 98008781050891.

The square root of 19805018780089 is 4450283.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 19805018780089 - 2⁷ = 19805018779961 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 19805018780089.

It is not an unprimeable number, because it can be changed into a prime (19805018780039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2225142 + ... + 6675424.

Almost surely, 2^{19805018780089} is an apocalyptic number.

19805018780089 is the 4450283-rd square number.

19805018780089 is the 2225142-nd centered octagonal number.

It is an amenable number.

19805018780089 is a deficient number, since it is larger than the sum of its proper divisors (4450284).

19805018780089 is an frugal number, since it uses more digits than its factorization.

19805018780089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8900566 (or 4450283 counting only the distinct ones).

The product of its (nonzero) digits is 11612160, while the sum is 64.

The spelling of 19805018780089 in words is "nineteen trillion, eight hundred five billion, eighteen million, seven hundred eighty thousand, eighty-nine".