12221718 has 32 divisors (see below), whose sum is σ = 25276416. Its totient is φ = 3937248.

The previous prime is 12221689. The next prime is 12221749. The reversal of 12221718 is 81712221.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32580 + ... + 32952.

It is an arithmetic number, because the mean of its divisors is an integer number (789888).

Almost surely, 2^12221718 is an apocalyptic number.

12221718 is an abundant number, since it is smaller than the sum of its proper divisors (13054698).

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

12221718 is a wasteful number, since it uses less digits than its factorization.

12221718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548.

The product of its digits is 448, while the sum is 24.

The square root of 12221718 is about 3495.9573796029. The cubic root of 12221718 is about 230.3442733305.

Adding to 12221718 its reverse (81712221), we get a palindrome (93933939).

The spelling of 12221718 in words is "twelve million, two hundred twenty-one thousand, seven hundred eighteen".