18418709 has 2 divisors, whose sum is σ = 18418710. Its totient is φ = 18418708.

The previous prime is 18418693. The next prime is 18418721. The reversal of 18418709 is 90781481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18190225 + 228484 = 4265^2 + 478^2 .

It is a cyclic number.

It is not a de Polignac number, because 18418709 - 2⁴ = 18418693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18418739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9209354 + 9209355.

It is an arithmetic number, because the mean of its divisors is an integer number (9209355).

Almost surely, 2^18418709 is an apocalyptic number.

It is an amenable number.

18418709 is a deficient number, since it is larger than the sum of its proper divisors (1).

18418709 is an equidigital number, since it uses as much as digits as its factorization.

18418709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 38.

The square root of 18418709 is about 4291.7023428938. The cubic root of 18418709 is about 264.0906722904.

The spelling of 18418709 in words is "eighteen million, four hundred eighteen thousand, seven hundred nine".