18315197 has 2 divisors, whose sum is σ = 18315198. Its totient is φ = 18315196.

The previous prime is 18315179. The next prime is 18315217. The reversal of 18315197 is 79151381.

Together with previous prime (18315179) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16273156 + 2042041 = 4034^2 + 1429^2 .

It is an emirp because it is prime and its reverse (79151381) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18315197 - 2⁶ = 18315133 is a prime.

It is a super-2 number, since 2×18315197² = 670892882297618, which contains 22 as substring.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18315127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9157598 + 9157599.

It is an arithmetic number, because the mean of its divisors is an integer number (9157599).

Almost surely, 2^18315197 is an apocalyptic number.

It is an amenable number.

18315197 is a deficient number, since it is larger than the sum of its proper divisors (1).

18315197 is an equidigital number, since it uses as much as digits as its factorization.

18315197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 35.

The square root of 18315197 is about 4279.6258013990. The cubic root of 18315197 is about 263.5950182235.

The spelling of 18315197 in words is "eighteen million, three hundred fifteen thousand, one hundred ninety-seven".