18750109 has 4 divisors (see below), whose sum is σ = 21428704. Its totient is φ = 16071516.

The previous prime is 18750101. The next prime is 18750113. The reversal of 18750109 is 90105781.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90105781 = 6263 ⋅14387.

It is a cyclic number.

It is not a de Polignac number, because 18750109 - 2³ = 18750101 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 (18750101) 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, 1339287 + ... + 1339300.

It is an arithmetic number, because the mean of its divisors is an integer number (5357176).

Almost surely, 2^18750109 is an apocalyptic number.

It is an amenable number.

18750109 is a deficient number, since it is larger than the sum of its proper divisors (2678595).

18750109 is an equidigital number, since it uses as much as digits as its factorization.

18750109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2678594.

The product of its (nonzero) digits is 2520, while the sum is 31.

The square root of 18750109 is about 4330.1396051398. The cubic root of 18750109 is about 265.6651570937.

The spelling of 18750109 in words is "eighteen million, seven hundred fifty thousand, one hundred nine".