11991838 has 8 divisors (see below), whose sum is σ = 18013680. Its totient is φ = 5987280.

The previous prime is 11991781. The next prime is 11991839. The reversal of 11991838 is 83819911.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 11991838.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11991839) 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, 2418 + ... + 5461.

It is an arithmetic number, because the mean of its divisors is an integer number (2251710).

Almost surely, 2^11991838 is an apocalyptic number.

11991838 is a deficient number, since it is larger than the sum of its proper divisors (6021842).

11991838 is an equidigital number, since it uses as much as digits as its factorization.

11991838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8642.

The product of its digits is 15552, while the sum is 40.

The square root of 11991838 is about 3462.9233315221. The cubic root of 11991838 is about 228.8909303065.

The spelling of 11991838 in words is "eleven million, nine hundred ninety-one thousand, eight hundred thirty-eight".