1216818 has 12 divisors (see below), whose sum is σ = 2636478. Its totient is φ = 405600.

The previous prime is 1216807. The next prime is 1216823. The reversal of 1216818 is 8186121.

It can be written as a sum of positive squares in only one way, i.e., 613089 + 603729 = 783^2 + 777^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1216791 and 1216800.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 33783 + ... + 33818.

2^1216818 is an apocalyptic number.

1216818 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1216818 is an abundant number, since it is smaller than the sum of its proper divisors (1419660).

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

1216818 is a wasteful number, since it uses less digits than its factorization.

1216818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67609 (or 67606 counting only the distinct ones).

The product of its digits is 768, while the sum is 27.

The square root of 1216818 is about 1103.0947375452. The cubic root of 1216818 is about 106.7599942744.

It can be divided in two parts, 12168 and 18, that multiplied together give a square (219024 = 468²).

The spelling of 1216818 in words is "one million, two hundred sixteen thousand, eight hundred eighteen".