18838409 has 2 divisors, whose sum is σ = 18838410. Its totient is φ = 18838408.

The previous prime is 18838387. The next prime is 18838411. The reversal of 18838409 is 90483881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18835600 + 2809 = 4340^2 + 53^2 .

It is a cyclic number.

It is not a de Polignac number, because 18838409 - 2⁸ = 18838153 is a prime.

Together with 18838411, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18838009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9419204 + 9419205.

It is an arithmetic number, because the mean of its divisors is an integer number (9419205).

Almost surely, 2^18838409 is an apocalyptic number.

It is an amenable number.

18838409 is a deficient number, since it is larger than the sum of its proper divisors (1).

18838409 is an equidigital number, since it uses as much as digits as its factorization.

18838409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 55296, while the sum is 41.

The square root of 18838409 is about 4340.3236054469. The cubic root of 18838409 is about 266.0815369916.

The spelling of 18838409 in words is "eighteen million, eight hundred thirty-eight thousand, four hundred nine".