12209778 has 96 divisors (see below), whose sum is σ = 32532864. Its totient is φ = 3359232.

The previous prime is 12209777. The next prime is 12209809. The reversal of 12209778 is 87790221.

It is not an unprimeable number, because it can be changed into a prime (12209777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 125826 + ... + 125922.

It is an arithmetic number, because the mean of its divisors is an integer number (338884).

Almost surely, 2^12209778 is an apocalyptic number.

12209778 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 12209778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16266432).

12209778 is an abundant number, since it is smaller than the sum of its proper divisors (20323086).

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

12209778 is an equidigital number, since it uses as much as digits as its factorization.

12209778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 12209778 is about 3494.2492755955. The cubic root of 12209778 is about 230.2692373236.

Adding to 12209778 its reverse (87790221), we get a palindrome (99999999).

The spelling of 12209778 in words is "twelve million, two hundred nine thousand, seven hundred seventy-eight".