18718738 has 4 divisors (see below), whose sum is σ = 28078110. Its totient is φ = 9359368.

The previous prime is 18718729. The next prime is 18718759. The reversal of 18718738 is 83781781.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83781781 = 769 ⋅108949.

It can be written as a sum of positive squares in only one way, i.e., 16136289 + 2582449 = 4017^2 + 1607^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18718694 and 18718703.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4679683 + ... + 4679686.

Almost surely, 2^18718738 is an apocalyptic number.

18718738 is a deficient number, since it is larger than the sum of its proper divisors (9359372).

18718738 is an equidigital number, since it uses as much as digits as its factorization.

18718738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9359371.

The product of its digits is 75264, while the sum is 43.

The square root of 18718738 is about 4326.5156881722. The cubic root of 18718738 is about 265.5169120182.

It can be divided in two parts, 1871 and 8738, that added together give a square (10609 = 103²).

The spelling of 18718738 in words is "eighteen million, seven hundred eighteen thousand, seven hundred thirty-eight".