18988549 has 4 divisors (see below), whose sum is σ = 19011564. Its totient is φ = 18965536.

The previous prime is 18988483. The next prime is 18988573. The reversal of 18988549 is 94588981.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16957924 + 2030625 = 4118^2 + 1425^2 .

It is a cyclic number.

It is not a de Polignac number, because 18988549 - 2⁷ = 18988421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18988496 and 18988505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18988579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10222 + ... + 11935.

It is an arithmetic number, because the mean of its divisors is an integer number (4752891).

Almost surely, 2^18988549 is an apocalyptic number.

It is an amenable number.

18988549 is a deficient number, since it is larger than the sum of its proper divisors (23015).

18988549 is an equidigital number, since it uses as much as digits as its factorization.

18988549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23014.

The product of its digits is 829440, while the sum is 52.

The square root of 18988549 is about 4357.5852257873. The cubic root of 18988549 is about 266.7865473146.

The spelling of 18988549 in words is "eighteen million, nine hundred eighty-eight thousand, five hundred forty-nine".