18548561 has 2 divisors, whose sum is σ = 18548562. Its totient is φ = 18548560.

The previous prime is 18548539. The next prime is 18548599. The reversal of 18548561 is 16584581.

It is an a-pointer prime, because the next prime (18548599) can be obtained adding 18548561 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11155600 + 7392961 = 3340^2 + 2719^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18548561 is a prime.

It is not a weakly prime, because it can be changed into another prime (18548501) 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 as a sum of consecutive naturals, namely, 9274280 + 9274281.

It is an arithmetic number, because the mean of its divisors is an integer number (9274281).

Almost surely, 2^18548561 is an apocalyptic number.

It is an amenable number.

18548561 is a deficient number, since it is larger than the sum of its proper divisors (1).

18548561 is an equidigital number, since it uses as much as digits as its factorization.

18548561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38400, while the sum is 38.

The square root of 18548561 is about 4306.8040354769. The cubic root of 18548561 is about 264.7098330981.

The spelling of 18548561 in words is "eighteen million, five hundred forty-eight thousand, five hundred sixty-one".