18663254647 has 4 divisors (see below), whose sum is σ = 18810209536. Its totient is φ = 18516299760.

The previous prime is 18663254633. The next prime is 18663254669. The reversal of 18663254647 is 74645236681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74645236681 = 215983 ⋅345607.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18663254647 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18663254594 and 18663254603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18663254627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73477254 + ... + 73477507.

It is an arithmetic number, because the mean of its divisors is an integer number (4702552384).

Almost surely, 2^18663254647 is an apocalyptic number.

18663254647 is a deficient number, since it is larger than the sum of its proper divisors (146954889).

18663254647 is a wasteful number, since it uses less digits than its factorization.

18663254647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146954888.

The product of its digits is 5806080, while the sum is 52.

The spelling of 18663254647 in words is "eighteen billion, six hundred sixty-three million, two hundred fifty-four thousand, six hundred forty-seven".