18987719623 has 2 divisors, whose sum is σ = 18987719624. Its totient is φ = 18987719622.

The previous prime is 18987719587. The next prime is 18987719629. The reversal of 18987719623 is 32691778981.

It is a strong prime.

It is an emirp because it is prime and its reverse (32691778981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18987719623 - 2⁹ = 18987719111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18987719629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9493859811 + 9493859812.

It is an arithmetic number, because the mean of its divisors is an integer number (9493859812).

Almost surely, 2^18987719623 is an apocalyptic number.

18987719623 is a deficient number, since it is larger than the sum of its proper divisors (1).

18987719623 is an equidigital number, since it uses as much as digits as its factorization.

18987719623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9144576, while the sum is 61.

The spelling of 18987719623 in words is "eighteen billion, nine hundred eighty-seven million, seven hundred nineteen thousand, six hundred twenty-three".