18242561 has 2 divisors, whose sum is σ = 18242562. Its totient is φ = 18242560.

The previous prime is 18242557. The next prime is 18242569. The reversal of 18242561 is 16524281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17272336 + 970225 = 4156^2 + 985^2 .

It is a cyclic number.

It is not a de Polignac number, because 18242561 - 2² = 18242557 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18242569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9121280 + 9121281.

It is an arithmetic number, because the mean of its divisors is an integer number (9121281).

Almost surely, 2^18242561 is an apocalyptic number.

It is an amenable number.

18242561 is a deficient number, since it is larger than the sum of its proper divisors (1).

18242561 is an equidigital number, since it uses as much as digits as its factorization.

18242561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3840, while the sum is 29.

The square root of 18242561 is about 4271.1311148219. The cubic root of 18242561 is about 263.2460938741.

The spelling of 18242561 in words is "eighteen million, two hundred forty-two thousand, five hundred sixty-one".