1221245 has 8 divisors (see below), whose sum is σ = 1512960. Its totient is φ = 945360.

The previous prime is 1221239. The next prime is 1221247. The reversal of 1221245 is 5421221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221245 - 2¹⁶ = 1155709 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221247) by changing a digit.

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, 3785 + ... + 4094.

It is an arithmetic number, because the mean of its divisors is an integer number (189120).

2^1221245 is an apocalyptic number.

It is an amenable number.

1221245 is a deficient number, since it is larger than the sum of its proper divisors (291715).

1221245 is an equidigital number, since it uses as much as digits as its factorization.

1221245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7915.

The product of its digits is 160, while the sum is 17.

The square root of 1221245 is about 1105.0995430277. The cubic root of 1221245 is about 106.8893081855.

Adding to 1221245 its reverse (5421221), we get a palindrome (6642466).

The spelling of 1221245 in words is "one million, two hundred twenty-one thousand, two hundred forty-five".