18737449 has 2 divisors, whose sum is σ = 18737450. Its totient is φ = 18737448.

The previous prime is 18737413. The next prime is 18737473. The reversal of 18737449 is 94473781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13191424 + 5546025 = 3632^2 + 2355^2 .

It is an emirp because it is prime and its reverse (94473781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18737449 - 2⁹ = 18736937 is a prime.

It is not a weakly prime, because it can be changed into another prime (18737489) 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 as a sum of consecutive naturals, namely, 9368724 + 9368725.

It is an arithmetic number, because the mean of its divisors is an integer number (9368725).

Almost surely, 2^18737449 is an apocalyptic number.

It is an amenable number.

18737449 is a deficient number, since it is larger than the sum of its proper divisors (1).

18737449 is an equidigital number, since it uses as much as digits as its factorization.

18737449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 169344, while the sum is 43.

The square root of 18737449 is about 4328.6775116657. The cubic root of 18737449 is about 265.6053516078.

It can be divided in two parts, 187 and 37449, that added together give a square (37636 = 194²).

The spelling of 18737449 in words is "eighteen million, seven hundred thirty-seven thousand, four hundred forty-nine".