18664977687 has 8 divisors (see below), whose sum is σ = 25968664704. Its totient is φ = 11902304568.

The previous prime is 18664977649. The next prime is 18664977691. The reversal of 18664977687 is 78677946681.

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

It is not a de Polignac number, because 18664977687 - 2⁶ = 18664977623 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (69), and also a Moran number because the ratio is a prime number: 270506923 = 18664977687 / (1 + 8 + 6 + 6 + 4 + 9 + 7 + 7 + 6 + 8 + 7).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18664977607) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135253393 + ... + 135253530.

It is an arithmetic number, because the mean of its divisors is an integer number (3246083088).

Almost surely, 2^18664977687 is an apocalyptic number.

18664977687 is a deficient number, since it is larger than the sum of its proper divisors (7303687017).

18664977687 is a wasteful number, since it uses less digits than its factorization.

18664977687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270506949.

The product of its digits is 170698752, while the sum is 69.

The spelling of 18664977687 in words is "eighteen billion, six hundred sixty-four million, nine hundred seventy-seven thousand, six hundred eighty-seven".