11916221 has 4 divisors (see below), whose sum is σ = 11950332. Its totient is φ = 11882112.

The previous prime is 11916197. The next prime is 11916241. The reversal of 11916221 is 12261911.

It is a happy number.

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 6180196 + 5736025 = 2486^2 + 2395^2 .

It is a cyclic number.

It is not a de Polignac number, because 11916221 - 2¹⁴ = 11899837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11916241) 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, 16526 + ... + 17231.

It is an arithmetic number, because the mean of its divisors is an integer number (2987583).

Almost surely, 2^11916221 is an apocalyptic number.

It is an amenable number.

11916221 is a deficient number, since it is larger than the sum of its proper divisors (34111).

11916221 is an equidigital number, since it uses as much as digits as its factorization.

11916221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34110.

The product of its digits is 216, while the sum is 23.

The square root of 11916221 is about 3451.9879779628. The cubic root of 11916221 is about 228.4088092373.

The spelling of 11916221 in words is "eleven million, nine hundred sixteen thousand, two hundred twenty-one".