11518221 has 16 divisors (see below), whose sum is σ = 18043200. Its totient is φ = 6443520.

The previous prime is 11518219. The next prime is 11518223. The reversal of 11518221 is 12281511.

11518221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (11518219) and next prime (11518223).

It is not a de Polignac number, because 11518221 - 2¹ = 11518219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11518223) 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, 12996 + ... + 13853.

It is an arithmetic number, because the mean of its divisors is an integer number (1127700).

Almost surely, 2^11518221 is an apocalyptic number.

11518221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11518221 is a deficient number, since it is larger than the sum of its proper divisors (6524979).

11518221 is a wasteful number, since it uses less digits than its factorization.

11518221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26876.

The product of its digits is 160, while the sum is 21.

The square root of 11518221 is about 3393.8504681261. The cubic root of 11518221 is about 225.8370206170.

Adding to 11518221 its reverse (12281511), we get a palindrome (23799732).

It can be divided in two parts, 115 and 18221, that added together give a triangular number (18336 = T₁₉₁).

The spelling of 11518221 in words is "eleven million, five hundred eighteen thousand, two hundred twenty-one".