18827909 has 2 divisors, whose sum is σ = 18827910. Its totient is φ = 18827908.

The previous prime is 18827899. The next prime is 18827923. The reversal of 18827909 is 90972881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18679684 + 148225 = 4322^2 + 385^2 .

It is an emirp because it is prime and its reverse (90972881) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18827909 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18827909.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18827009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9413954 + 9413955.

It is an arithmetic number, because the mean of its divisors is an integer number (9413955).

Almost surely, 2^18827909 is an apocalyptic number.

It is an amenable number.

18827909 is a deficient number, since it is larger than the sum of its proper divisors (1).

18827909 is an equidigital number, since it uses as much as digits as its factorization.

18827909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 44.

The square root of 18827909 is about 4339.1138496241. The cubic root of 18827909 is about 266.0320923460.

The spelling of 18827909 in words is "eighteen million, eight hundred twenty-seven thousand, nine hundred nine".