18061997 has 2 divisors, whose sum is σ = 18061998. Its totient is φ = 18061996.

The previous prime is 18061993. The next prime is 18062047. The reversal of 18061997 is 79916081.

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., 17732521 + 329476 = 4211^2 + 574^2 .

It is a cyclic number.

It is not a de Polignac number, because 18061997 - 2² = 18061993 is a prime.

It is a Chen prime.

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 (18061991) 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, 9030998 + 9030999.

It is an arithmetic number, because the mean of its divisors is an integer number (9030999).

Almost surely, 2^18061997 is an apocalyptic number.

It is an amenable number.

18061997 is a deficient number, since it is larger than the sum of its proper divisors (1).

18061997 is an equidigital number, since it uses as much as digits as its factorization.

18061997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27216, while the sum is 41.

The square root of 18061997 is about 4249.9408231174. The cubic root of 18061997 is about 262.3746800143.

The spelling of 18061997 in words is "eighteen million, sixty-one thousand, nine hundred ninety-seven".