19871781663 has 8 divisors (see below), whose sum is σ = 26497203376. Its totient is φ = 13247107200.

The previous prime is 19871781599. The next prime is 19871781689. The reversal of 19871781663 is 36618717891.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19871781663 - 2⁶ = 19871781599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19871781263) 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 7 ways as a sum of consecutive naturals, for example, 121498 + ... + 233463.

It is an arithmetic number, because the mean of its divisors is an integer number (3312150422).

Almost surely, 2^19871781663 is an apocalyptic number.

19871781663 is a deficient number, since it is larger than the sum of its proper divisors (6625421713).

19871781663 is a wasteful number, since it uses less digits than its factorization.

19871781663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373625.

The product of its digits is 3048192, while the sum is 57.

The spelling of 19871781663 in words is "nineteen billion, eight hundred seventy-one million, seven hundred eighty-one thousand, six hundred sixty-three".