18381197 has 2 divisors, whose sum is σ = 18381198. Its totient is φ = 18381196.

The previous prime is 18381173. The next prime is 18381203. The reversal of 18381197 is 79118381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11485321 + 6895876 = 3389^2 + 2626^2 .

It is an emirp because it is prime and its reverse (79118381) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18381197 - 2⁸ = 18380941 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18381197.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18381107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9190598 + 9190599.

It is an arithmetic number, because the mean of its divisors is an integer number (9190599).

Almost surely, 2^18381197 is an apocalyptic number.

It is an amenable number.

18381197 is a deficient number, since it is larger than the sum of its proper divisors (1).

18381197 is an equidigital number, since it uses as much as digits as its factorization.

18381197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 38.

The square root of 18381197 is about 4287.3298216956. The cubic root of 18381197 is about 263.9112659009.

The spelling of 18381197 in words is "eighteen million, three hundred eighty-one thousand, one hundred ninety-seven".