1221366 has 16 divisors (see below), whose sum is σ = 2455488. Its totient is φ = 405000.

The previous prime is 1221299. The next prime is 1221373. The reversal of 1221366 is 6631221.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1101 + ... + 1911.

It is an arithmetic number, because the mean of its divisors is an integer number (153468).

2^1221366 is an apocalyptic number.

1221366 is an abundant number, since it is smaller than the sum of its proper divisors (1234122).

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

1221366 is a wasteful number, since it uses less digits than its factorization.

1221366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1067.

The product of its digits is 432, while the sum is 21.

The square root of 1221366 is about 1105.1542878712. The cubic root of 1221366 is about 106.8928382386.

Adding to 1221366 its reverse (6631221), we get a palindrome (7852587).

The spelling of 1221366 in words is "one million, two hundred twenty-one thousand, three hundred sixty-six".