18128749 has 8 divisors (see below), whose sum is σ = 19241280. Its totient is φ = 17021376.

The previous prime is 18128729. The next prime is 18128791. The reversal of 18128749 is 94782181.

It is a happy number.

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 18128749 - 2⁹ = 18128237 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18128729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7872 + ... + 9910.

It is an arithmetic number, because the mean of its divisors is an integer number (2405160).

Almost surely, 2^18128749 is an apocalyptic number.

It is an amenable number.

18128749 is a deficient number, since it is larger than the sum of its proper divisors (1112531).

18128749 is a wasteful number, since it uses less digits than its factorization.

18128749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2579.

The product of its digits is 32256, while the sum is 40.

The square root of 18128749 is about 4257.7868664366. The cubic root of 18128749 is about 262.6975033655.

The spelling of 18128749 in words is "eighteen million, one hundred twenty-eight thousand, seven hundred forty-nine".