1221678 has 24 divisors (see below), whose sum is σ = 2689128. Its totient is φ = 400752.

The previous prime is 1221667. The next prime is 1221707. The reversal of 1221678 is 8761221.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 700 + ... + 1712.

It is an arithmetic number, because the mean of its divisors is an integer number (112047).

2^1221678 is an apocalyptic number.

1221678 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1221678 is an abundant number, since it is smaller than the sum of its proper divisors (1467450).

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

1221678 is a wasteful number, since it uses less digits than its factorization.

1221678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1088 (or 1085 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 1221678 is about 1105.2954356189. The cubic root of 1221678 is about 106.9019394488.

Adding to 1221678 its reverse (8761221), we get a palindrome (9982899).

The spelling of 1221678 in words is "one million, two hundred twenty-one thousand, six hundred seventy-eight".