18531648 has 42 divisors (see below), whose sum is σ = 53119274. Its totient is φ = 6177024.

The previous prime is 18531641. The next prime is 18531673. The reversal of 18531648 is 84613581.

18531648 is a `hidden beast` number, since 1 + 8 + 5 + 3 + 1 + 648 = 666.

It can be written as a sum of positive squares in only one way, i.e., 15116544 + 3415104 = 3888^2 + 1848^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18531641) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 15511 + ... + 16662.

Almost surely, 2^18531648 is an apocalyptic number.

18531648 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

18531648 is an abundant number, since it is smaller than the sum of its proper divisors (34587626).

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

18531648 is a wasteful number, since it uses less digits than its factorization.

18531648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32191 (or 32178 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 18531648 is about 4304.8400667156. The cubic root of 18531648 is about 264.6293524820.

The spelling of 18531648 in words is "eighteen million, five hundred thirty-one thousand, six hundred forty-eight".