18745919 has 4 divisors (see below), whose sum is σ = 19392360. Its totient is φ = 18099480.

The previous prime is 18745901. The next prime is 18745921. The reversal of 18745919 is 91954781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91954781 = 2131 ⋅43151.

It is a de Polignac number, because none of the positive numbers 2^k-18745919 is a prime.

It is a super-2 number, since 2×18745919² = 702818958309122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18745919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18745949) 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, 323177 + ... + 323234.

It is an arithmetic number, because the mean of its divisors is an integer number (4848090).

Almost surely, 2^18745919 is an apocalyptic number.

18745919 is a deficient number, since it is larger than the sum of its proper divisors (646441).

18745919 is an equidigital number, since it uses as much as digits as its factorization.

18745919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 646440.

The product of its digits is 90720, while the sum is 44.

The square root of 18745919 is about 4329.6557599883. The cubic root of 18745919 is about 265.6453666321.

The spelling of 18745919 in words is "eighteen million, seven hundred forty-five thousand, nine hundred nineteen".