19988587161 has 45 divisors (see below), whose sum is σ = 31259946949. Its totient is φ = 12727683144.

The previous prime is 19988587153. The next prime is 19988587181. The reversal of 19988587161 is 16178588991.

The square root of 19988587161 is 141381.

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

It is not a de Polignac number, because 19988587161 - 2³ = 19988587153 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19988587111) 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 44 ways as a sum of consecutive naturals, for example, 29265526 + ... + 29266208.

Almost surely, 2^19988587161 is an apocalyptic number.

19988587161 is the 141381-st square number.

19988587161 is the 70691-st centered octagonal number.

It is an amenable number.

19988587161 is a deficient number, since it is larger than the sum of its proper divisors (11271359788).

19988587161 is an frugal number, since it uses more digits than its factorization.

19988587161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1424 (or 709 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 63.

The spelling of 19988587161 in words is "nineteen billion, nine hundred eighty-eight million, five hundred eighty-seven thousand, one hundred sixty-one".