18012643 has 16 divisors (see below), whose sum is σ = 20524032. Its totient is φ = 15660000.

The previous prime is 18012613. The next prime is 18012647. The reversal of 18012643 is 34621081.

It is a cyclic number.

It is not a de Polignac number, because 18012643 - 2⁹ = 18012131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18012647) 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 15 ways as a sum of consecutive naturals, for example, 34180 + ... + 34702.

It is an arithmetic number, because the mean of its divisors is an integer number (1282752).

Almost surely, 2^18012643 is an apocalyptic number.

18012643 is a deficient number, since it is larger than the sum of its proper divisors (2511389).

18012643 is a wasteful number, since it uses less digits than its factorization.

18012643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 666.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 18012643 is about 4244.1304174118. The cubic root of 18012643 is about 262.1354843817.

It can be divided in two parts, 1801 and 2643, that added together give a palindrome (4444).

The spelling of 18012643 in words is "eighteen million, twelve thousand, six hundred forty-three".