18212005 has 16 divisors (see below), whose sum is σ = 25559424. Its totient is φ = 12196800.

The previous prime is 18211993. The next prime is 18212009. The reversal of 18212005 is 50021281.

It is not a de Polignac number, because 18212005 - 2⁷ = 18211877 is a prime.

It is a super-2 number, since 2×18212005² = 663354252240050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18212009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4546 + ... + 7555.

It is an arithmetic number, because the mean of its divisors is an integer number (1597464).

Almost surely, 2^18212005 is an apocalyptic number.

It is an amenable number.

18212005 is a deficient number, since it is larger than the sum of its proper divisors (7347419).

18212005 is a wasteful number, since it uses less digits than its factorization.

18212005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12156.

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 18212005 is about 4267.5525772977. The cubic root of 18212005 is about 263.0990340601.

Adding to 18212005 its reverse (50021281), we get a palindrome (68233286).

The spelling of 18212005 in words is "eighteen million, two hundred twelve thousand, five".