12221778 has 8 divisors (see below), whose sum is σ = 24443568. Its totient is φ = 4073924.

The previous prime is 12221771. The next prime is 12221801. The reversal of 12221778 is 87712221.

It is a happy number.

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

12221778 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (12221771) 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, 1018476 + ... + 1018487.

It is an arithmetic number, because the mean of its divisors is an integer number (3055446).

Almost surely, 2^12221778 is an apocalyptic number.

12221778 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

12221778 is a wasteful number, since it uses less digits than its factorization.

12221778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2036968.

The product of its digits is 3136, while the sum is 30.

The square root of 12221778 is about 3495.9659609327. The cubic root of 12221778 is about 230.3446502724.

Adding to 12221778 its reverse (87712221), we get a palindrome (99933999).

The spelling of 12221778 in words is "twelve million, two hundred twenty-one thousand, seven hundred seventy-eight".