18603313 has 2 divisors, whose sum is σ = 18603314. Its totient is φ = 18603312.

The previous prime is 18603311. The next prime is 18603323. The reversal of 18603313 is 31330681.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11675889 + 6927424 = 3417^2 + 2632^2 .

It is an emirp because it is prime and its reverse (31330681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18603313 - 2¹ = 18603311 is a prime.

Together with 18603311, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18603311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9301656 + 9301657.

It is an arithmetic number, because the mean of its divisors is an integer number (9301657).

Almost surely, 2^18603313 is an apocalyptic number.

It is an amenable number.

18603313 is a deficient number, since it is larger than the sum of its proper divisors (1).

18603313 is an equidigital number, since it uses as much as digits as its factorization.

18603313 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 18603313 is about 4313.1558052081. The cubic root of 18603313 is about 264.9700357718.

Adding to 18603313 its reverse (31330681), we get a palindrome (49933994).

The spelling of 18603313 in words is "eighteen million, six hundred three thousand, three hundred thirteen".