18897709 has 2 divisors, whose sum is σ = 18897710. Its totient is φ = 18897708.

The previous prime is 18897701. The next prime is 18897737. The reversal of 18897709 is 90779881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15382084 + 3515625 = 3922^2 + 1875^2 .

It is a cyclic number.

It is not a de Polignac number, because 18897709 - 2³ = 18897701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18897701) 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, 9448854 + 9448855.

It is an arithmetic number, because the mean of its divisors is an integer number (9448855).

Almost surely, 2^18897709 is an apocalyptic number.

It is an amenable number.

18897709 is a deficient number, since it is larger than the sum of its proper divisors (1).

18897709 is an equidigital number, since it uses as much as digits as its factorization.

18897709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 254016, while the sum is 49.

The square root of 18897709 is about 4347.1495258387. The cubic root of 18897709 is about 266.3604371880.

The spelling of 18897709 in words is "eighteen million, eight hundred ninety-seven thousand, seven hundred nine".