18738197 has 2 divisors, whose sum is σ = 18738198. Its totient is φ = 18738196.

The previous prime is 18738179. The next prime is 18738217. The reversal of 18738197 is 79183781.

Together with previous prime (18738179) 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., 15319396 + 3418801 = 3914^2 + 1849^2 .

It is an emirp because it is prime and its reverse (79183781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18738197 - 2⁸ = 18737941 is a prime.

It is a super-2 number, since 2×18738197² = 702240053621618, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18708197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9369098 + 9369099.

It is an arithmetic number, because the mean of its divisors is an integer number (9369099).

Almost surely, 2^18738197 is an apocalyptic number.

It is an amenable number.

18738197 is a deficient number, since it is larger than the sum of its proper divisors (1).

18738197 is an equidigital number, since it uses as much as digits as its factorization.

18738197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 84672, while the sum is 44.

The square root of 18738197 is about 4328.7639113262. The cubic root of 18738197 is about 265.6088858875.

The spelling of 18738197 in words is "eighteen million, seven hundred thirty-eight thousand, one hundred ninety-seven".