18040397 has 2 divisors, whose sum is σ = 18040398. Its totient is φ = 18040396.

The previous prime is 18040387. The next prime is 18040411. The reversal of 18040397 is 79304081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18028516 + 11881 = 4246^2 + 109^2 .

It is a cyclic number.

It is not a de Polignac number, because 18040397 - 2⁶ = 18040333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18040327) 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, 9020198 + 9020199.

It is an arithmetic number, because the mean of its divisors is an integer number (9020199).

Almost surely, 2^18040397 is an apocalyptic number.

It is an amenable number.

18040397 is a deficient number, since it is larger than the sum of its proper divisors (1).

18040397 is an equidigital number, since it uses as much as digits as its factorization.

18040397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 18040397 is about 4247.3988510617. The cubic root of 18040397 is about 262.2700486581.

The spelling of 18040397 in words is "eighteen million, forty thousand, three hundred ninety-seven".