18400313 has 2 divisors, whose sum is σ = 18400314. Its totient is φ = 18400312.

The previous prime is 18400301. The next prime is 18400351. The reversal of 18400313 is 31300481.

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., 18292729 + 107584 = 4277^2 + 328^2 .

It is an emirp because it is prime and its reverse (31300481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18400313 - 2¹⁰ = 18399289 is a prime.

It is not a weakly prime, because it can be changed into another prime (18400373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9200156 + 9200157.

It is an arithmetic number, because the mean of its divisors is an integer number (9200157).

Almost surely, 2^18400313 is an apocalyptic number.

It is an amenable number.

18400313 is a deficient number, since it is larger than the sum of its proper divisors (1).

18400313 is an equidigital number, since it uses as much as digits as its factorization.

18400313 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 18400313 is about 4289.5586020009. The cubic root of 18400313 is about 264.0027213142.

Adding to 18400313 its reverse (31300481), we get a palindrome (49700794).

The spelling of 18400313 in words is "eighteen million, four hundred thousand, three hundred thirteen".