18641664 has 180 divisors, whose sum is σ = 59357760. Its totient is φ = 5806080.

The previous prime is 18641653. The next prime is 18641713. The reversal of 18641664 is 46614681.

18641664 is a `hidden beast` number, since 1 + 8 + 641 + 6 + 6 + 4 = 666.

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 polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 601329 + ... + 601359.

Almost surely, 2^18641664 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 18641664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29678880).

18641664 is an abundant number, since it is smaller than the sum of its proper divisors (40716096).

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

18641664 is an equidigital number, since it uses as much as digits as its factorization.

18641664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88 (or 65 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 18641664 is about 4317.5993329627. The cubic root of 18641664 is about 265.1519906542.

The spelling of 18641664 in words is "eighteen million, six hundred forty-one thousand, six hundred sixty-four".