18036397 has 4 divisors (see below), whose sum is σ = 18055836. Its totient is φ = 18016960.

The previous prime is 18036383. The next prime is 18036401. The reversal of 18036397 is 79363081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79363081 = 7 ⋅11337583.

It can be written as a sum of positive squares in 2 ways, for example, as 8678916 + 9357481 = 2946^2 + 3059^2 .

It is a cyclic number.

It is not a de Polignac number, because 18036397 - 2¹¹ = 18034349 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18036367) 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 in 3 ways as a sum of consecutive naturals, for example, 8254 + ... + 10207.

It is an arithmetic number, because the mean of its divisors is an integer number (4513959).

Almost surely, 2^18036397 is an apocalyptic number.

It is an amenable number.

18036397 is a deficient number, since it is larger than the sum of its proper divisors (19439).

18036397 is an equidigital number, since it uses as much as digits as its factorization.

18036397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19438.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 18036397 is about 4246.9279485294. The cubic root of 18036397 is about 262.2506633171.

The spelling of 18036397 in words is "eighteen million, thirty-six thousand, three hundred ninety-seven".