18021406 has 16 divisors (see below), whose sum is σ = 29383200. Its totient is φ = 8239968.

The previous prime is 18021379. The next prime is 18021407. The reversal of 18021406 is 60412081.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18021407) 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 7 ways as a sum of consecutive naturals, for example, 346 + ... + 6013.

It is an arithmetic number, because the mean of its divisors is an integer number (1836450).

Almost surely, 2^18021406 is an apocalyptic number.

18021406 is a deficient number, since it is larger than the sum of its proper divisors (11361794).

18021406 is a wasteful number, since it uses less digits than its factorization.

18021406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6483.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 18021406 is about 4245.1626588389. The cubic root of 18021406 is about 262.1779863962.

Adding to 18021406 its reverse (60412081), we get a palindrome (78433487).

The spelling of 18021406 in words is "eighteen million, twenty-one thousand, four hundred six".