18281664 has 84 divisors (see below), whose sum is σ = 55513224. Its totient is φ = 5732352.

The previous prime is 18281651. The next prime is 18281677. The reversal of 18281664 is 46618281.

It is an interprime number because it is at equal distance from previous prime (18281651) and next prime (18281677).

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

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8859 + ... + 10725.

Almost surely, 2^18281664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18281664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27756612).

18281664 is an abundant number, since it is smaller than the sum of its proper divisors (37231560).

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

18281664 is a wasteful number, since it uses less digits than its factorization.

18281664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1902 (or 1889 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 18281664 is about 4275.7062574503. The cubic root of 18281664 is about 263.4340493167.

The spelling of 18281664 in words is "eighteen million, two hundred eighty-one thousand, six hundred sixty-four".