18021910 has 16 divisors (see below), whose sum is σ = 32756256. Its totient is φ = 7138368.

The previous prime is 18021907. The next prime is 18021947. The reversal of 18021910 is 1912081.

It is a congruent number.

It is an unprimeable number.

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, 7719 + ... + 9778.

It is an arithmetic number, because the mean of its divisors is an integer number (2047266).

Almost surely, 2^18021910 is an apocalyptic number.

18021910 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18021910 is a deficient number, since it is larger than the sum of its proper divisors (14734346).

18021910 is a wasteful number, since it uses less digits than its factorization.

18021910 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17607.

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 18021910 is about 4245.2220201068. Note that the first 3 decimals coincide. The cubic root of 18021910 is about 262.1804304614.

Adding to 18021910 its reverse (1912081), we get a palindrome (19933991).

The spelling of 18021910 in words is "eighteen million, twenty-one thousand, nine hundred ten".