18021369 has 4 divisors (see below), whose sum is σ = 24028496. Its totient is φ = 12014244.

The previous prime is 18021347. The next prime is 18021371. The reversal of 18021369 is 96312081.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 96312081 = 3 ⋅32104027.

It is not a de Polignac number, because 18021369 - 2⁵ = 18021337 is a prime.

It is a super-2 number, since 2×18021369² = 649539481268322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18021319) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3003559 + ... + 3003564.

It is an arithmetic number, because the mean of its divisors is an integer number (6007124).

Almost surely, 2^18021369 is an apocalyptic number.

It is an amenable number.

18021369 is a deficient number, since it is larger than the sum of its proper divisors (6007127).

18021369 is an equidigital number, since it uses as much as digits as its factorization.

18021369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6007126.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 18021369 is about 4245.1583009353. The cubic root of 18021369 is about 262.1778069690.

The spelling of 18021369 in words is "eighteen million, twenty-one thousand, three hundred sixty-nine".