18561447863 has 8 divisors (see below), whose sum is σ = 21232607232. Its totient is φ = 15895169496.

The previous prime is 18561447823. The next prime is 18561447887. The reversal of 18561447863 is 36874416581.

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

It is a cyclic number.

It is not a de Polignac number, because 18561447863 - 2¹⁸ = 18561185719 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 (18561447803) 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 in 7 ways as a sum of consecutive naturals, for example, 1212095 + ... + 1227312.

It is an arithmetic number, because the mean of its divisors is an integer number (2654075904).

Almost surely, 2^18561447863 is an apocalyptic number.

18561447863 is a deficient number, since it is larger than the sum of its proper divisors (2671159369).

18561447863 is a wasteful number, since it uses less digits than its factorization.

18561447863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2440501.

The product of its digits is 3870720, while the sum is 53.

The spelling of 18561447863 in words is "eighteen billion, five hundred sixty-one million, four hundred forty-seven thousand, eight hundred sixty-three".