18666672 has 40 divisors (see below), whose sum is σ = 48548976. Its totient is φ = 6180096.

The previous prime is 18666667. The next prime is 18666677. The reversal of 18666672 is 27666681.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18666667) and next prime (18666677).

It is not an unprimeable number, because it can be changed into a prime (18666677) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 6298 + ... + 8774.

Almost surely, 2^18666672 is an apocalyptic number.

18666672 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18666672 is an abundant number, since it is smaller than the sum of its proper divisors (29882304).

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

18666672 is a wasteful number, since it uses less digits than its factorization.

18666672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2645 (or 2639 counting only the distinct ones).

The product of its digits is 145152, while the sum is 42.

The square root of 18666672 is about 4320.4944161519. The cubic root of 18666672 is about 265.2705057903.

Subtracting 18666672 from its reverse (27666681), we obtain a palindrome (9000009).

The spelling of 18666672 in words is "eighteen million, six hundred sixty-six thousand, six hundred seventy-two".