18159865632 has 120 divisors (see below), whose sum is σ = 54710606412. Its totient is φ = 5905612800.

The previous prime is 18159865631. The next prime is 18159865637. The reversal of 18159865632 is 23656895181.

18159865632 is a `hidden beast` number, since 18 + 1 + 598 + 6 + 5 + 6 + 32 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 18137624976 + 22240656 = 134676^2 + 4716^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (18159865631) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 20832 + ... + 191712.

Almost surely, 2^18159865632 is an apocalyptic number.

18159865632 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18159865632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27355303206).

18159865632 is an abundant number, since it is smaller than the sum of its proper divisors (36550740780).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18159865632 is a wasteful number, since it uses less digits than its factorization.

18159865632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170944 (or 170927 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 54.

The spelling of 18159865632 in words is "eighteen billion, one hundred fifty-nine million, eight hundred sixty-five thousand, six hundred thirty-two".