18684749 has 8 divisors (see below), whose sum is σ = 19035000. Its totient is φ = 18337792.

The previous prime is 18684739. The next prime is 18684761. The reversal of 18684749 is 94748681.

It can be written as a sum of positive squares in 4 ways, for example, as 1932100 + 16752649 = 1390^2 + 4093^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18684749 - 2⁸ = 18684493 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18684719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12557 + ... + 13965.

It is an arithmetic number, because the mean of its divisors is an integer number (2379375).

Almost surely, 2^18684749 is an apocalyptic number.

It is an amenable number.

18684749 is a deficient number, since it is larger than the sum of its proper divisors (350251).

18684749 is a wasteful number, since it uses less digits than its factorization.

18684749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1647.

The product of its digits is 387072, while the sum is 47.

The square root of 18684749 is about 4322.5859158610. The cubic root of 18684749 is about 265.3561084056.

The spelling of 18684749 in words is "eighteen million, six hundred eighty-four thousand, seven hundred forty-nine".