18717449 has 4 divisors (see below), whose sum is σ = 19223364. Its totient is φ = 18211536.

The previous prime is 18717437. The next prime is 18717467. The reversal of 18717449 is 94471781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94471781 = 19 ⋅4972199.

It can be written as a sum of positive squares in 2 ways, for example, as 11055625 + 7661824 = 3325^2 + 2768^2 .

It is a cyclic number.

It is not a de Polignac number, because 18717449 - 2¹² = 18713353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18717649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 252902 + ... + 252975.

It is an arithmetic number, because the mean of its divisors is an integer number (4805841).

Almost surely, 2^18717449 is an apocalyptic number.

It is an amenable number.

18717449 is a deficient number, since it is larger than the sum of its proper divisors (505915).

18717449 is an equidigital number, since it uses as much as digits as its factorization.

18717449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 505914.

The product of its digits is 56448, while the sum is 41.

The square root of 18717449 is about 4326.3667204711. The cubic root of 18717449 is about 265.5108172492.

The spelling of 18717449 in words is "eighteen million, seven hundred seventeen thousand, four hundred forty-nine".