1216778 has 4 divisors (see below), whose sum is σ = 1825170. Its totient is φ = 608388.

The previous prime is 1216777. The next prime is 1216793. The reversal of 1216778 is 8776121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1216609 + 169 = 1103^2 + 13^2 .

It is not an unprimeable number, because it can be changed into a prime (1216777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 304193 + ... + 304196.

2^1216778 is an apocalyptic number.

1216778 is a deficient number, since it is larger than the sum of its proper divisors (608392).

1216778 is an equidigital number, since it uses as much as digits as its factorization.

1216778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608391.

The product of its digits is 4704, while the sum is 32.

The square root of 1216778 is about 1103.0766065872. The cubic root of 1216778 is about 106.7588244345.

The spelling of 1216778 in words is "one million, two hundred sixteen thousand, seven hundred seventy-eight".