18211312 has 20 divisors (see below), whose sum is σ = 40325296. Its totient is φ = 7804800.

The previous prime is 18211309. The next prime is 18211313. The reversal of 18211312 is 21311281.

It is a super-2 number, since 2×18211312² = 663303769522688, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18211312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18211313) 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, 81189 + ... + 81412.

Almost surely, 2^18211312 is an apocalyptic number.

It is an amenable number.

18211312 is an abundant number, since it is smaller than the sum of its proper divisors (22113984).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18211312 is a wasteful number, since it uses less digits than its factorization.

18211312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162616 (or 162610 counting only the distinct ones).

The product of its digits is 96, while the sum is 19.

The square root of 18211312 is about 4267.4713824465. The cubic root of 18211312 is about 263.0956968851.

Adding to 18211312 its reverse (21311281), we get a palindrome (39522593).

The spelling of 18211312 in words is "eighteen million, two hundred eleven thousand, three hundred twelve".