18211136 has 56 divisors (see below), whose sum is σ = 38136576. Its totient is φ = 8616960.

The previous prime is 18211133. The next prime is 18211153. The reversal of 18211136 is 63111281.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18211133) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132860 + ... + 132996.

Almost surely, 2^18211136 is an apocalyptic number.

18211136 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18211136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19068288).

18211136 is an abundant number, since it is smaller than the sum of its proper divisors (19925440).

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

18211136 is a wasteful number, since it uses less digits than its factorization.

18211136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247 (or 237 counting only the distinct ones).

The product of its digits is 288, while the sum is 23.

The square root of 18211136 is about 4267.4507612859. The cubic root of 18211136 is about 263.0948493352.

The spelling of 18211136 in words is "eighteen million, two hundred eleven thousand, one hundred thirty-six".