18664650 has 144 divisors (see below), whose sum is σ = 55130400. Its totient is φ = 4510080.

The previous prime is 18664649. The next prime is 18664651. The reversal of 18664650 is 5646681.

18664650 is a `hidden beast` number, since 1 + 8 + 6 + 646 + 5 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (18664649) and next prime (18664651).

It is not an unprimeable number, because it can be changed into a prime (18664651) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 316321 + ... + 316379.

It is an arithmetic number, because the mean of its divisors is an integer number (382850).

Almost surely, 2^18664650 is an apocalyptic number.

18664650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18664650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27565200).

18664650 is an abundant number, since it is smaller than the sum of its proper divisors (36465750).

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

18664650 is a wasteful number, since it uses less digits than its factorization.

18664650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133 (or 125 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 18664650 is about 4320.2604088180. The cubic root of 18664650 is about 265.2609272871.

The spelling of 18664650 in words is "eighteen million, six hundred sixty-four thousand, six hundred fifty".