18729133 has 4 divisors (see below), whose sum is σ = 18865980. Its totient is φ = 18592288.

The previous prime is 18729119. The next prime is 18729163. The reversal of 18729133 is 33192781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 33192781 = 359 ⋅92459.

It can be written as a sum of positive squares in 2 ways, for example, as 11854249 + 6874884 = 3443^2 + 2622^2 .

It is a cyclic number.

It is not a de Polignac number, because 18729133 - 2⁹ = 18728621 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18729103) 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 3 ways as a sum of consecutive naturals, for example, 68218 + ... + 68491.

It is an arithmetic number, because the mean of its divisors is an integer number (4716495).

Almost surely, 2^18729133 is an apocalyptic number.

It is an amenable number.

18729133 is a deficient number, since it is larger than the sum of its proper divisors (136847).

18729133 is a wasteful number, since it uses less digits than its factorization.

18729133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136846.

The product of its digits is 9072, while the sum is 34.

The square root of 18729133 is about 4327.7168345445. The cubic root of 18729133 is about 265.5660523956.

The spelling of 18729133 in words is "eighteen million, seven hundred twenty-nine thousand, one hundred thirty-three".