18731585663 has 16 divisors (see below), whose sum is σ = 22685866560. Its totient is φ = 15123897600.

The previous prime is 18731585657. The next prime is 18731585683. The reversal of 18731585663 is 36658513781.

It is a happy number.

It is not a de Polignac number, because 18731585663 - 2¹² = 18731581567 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18731585633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1116968 + ... + 1133613.

It is an arithmetic number, because the mean of its divisors is an integer number (1417866660).

Almost surely, 2^18731585663 is an apocalyptic number.

18731585663 is a deficient number, since it is larger than the sum of its proper divisors (3954280897).

18731585663 is a wasteful number, since it uses less digits than its factorization.

18731585663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2250658.

The product of its digits is 3628800, while the sum is 53.

The spelling of 18731585663 in words is "eighteen billion, seven hundred thirty-one million, five hundred eighty-five thousand, six hundred sixty-three".