18397481 has 2 divisors, whose sum is σ = 18397482. Its totient is φ = 18397480.

The previous prime is 18397471. The next prime is 18397487. The reversal of 18397481 is 18479381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15366400 + 3031081 = 3920^2 + 1741^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18397481 is a prime.

It is a super-2 number, since 2×18397481² = 676934614290722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18397487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9198740 + 9198741.

It is an arithmetic number, because the mean of its divisors is an integer number (9198741).

Almost surely, 2^18397481 is an apocalyptic number.

It is an amenable number.

18397481 is a deficient number, since it is larger than the sum of its proper divisors (1).

18397481 is an equidigital number, since it uses as much as digits as its factorization.

18397481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 41.

The square root of 18397481 is about 4289.2284854039. The cubic root of 18397481 is about 263.9891763622.

The spelling of 18397481 in words is "eighteen million, three hundred ninety-seven thousand, four hundred eighty-one".