11388221 has 4 divisors (see below), whose sum is σ = 12264252. Its totient is φ = 10512192.

The previous prime is 11388199. The next prime is 11388227. The reversal of 11388221 is 12288311.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4044121 + 7344100 = 2011^2 + 2710^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11388221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11388227) 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, 437996 + ... + 438021.

It is an arithmetic number, because the mean of its divisors is an integer number (3066063).

Almost surely, 2^11388221 is an apocalyptic number.

It is an amenable number.

11388221 is a deficient number, since it is larger than the sum of its proper divisors (876031).

11388221 is an equidigital number, since it uses as much as digits as its factorization.

11388221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 876030.

The product of its digits is 768, while the sum is 26.

The square root of 11388221 is about 3374.6438330585. The cubic root of 11388221 is about 224.9841700797.

The spelling of 11388221 in words is "eleven million, three hundred eighty-eight thousand, two hundred twenty-one".