18328691 has 2 divisors, whose sum is σ = 18328692. Its totient is φ = 18328690.

The previous prime is 18328663. The next prime is 18328693. The reversal of 18328691 is 19682381.

It is a strong prime.

It is an emirp because it is prime and its reverse (19682381) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18328691 - 2⁶ = 18328627 is a prime.

Together with 18328693, 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 (18328693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9164345 + 9164346.

It is an arithmetic number, because the mean of its divisors is an integer number (9164346).

Almost surely, 2^18328691 is an apocalyptic number.

18328691 is a deficient number, since it is larger than the sum of its proper divisors (1).

18328691 is an equidigital number, since it uses as much as digits as its factorization.

18328691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 38.

The square root of 18328691 is about 4281.2020508264. The cubic root of 18328691 is about 263.6597382114.

The spelling of 18328691 in words is "eighteen million, three hundred twenty-eight thousand, six hundred ninety-one".