1221345 has 32 divisors (see below), whose sum is σ = 2217600. Its totient is φ = 637632.

The previous prime is 1221299. The next prime is 1221373. The reversal of 1221345 is 5431221.

It is not a de Polignac number, because 1221345 - 2⁸ = 1221089 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11151 + ... + 11259.

It is an arithmetic number, because the mean of its divisors is an integer number (69300).

2^1221345 is an apocalyptic number.

1221345 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1221345 is a deficient number, since it is larger than the sum of its proper divisors (996255).

1221345 is a wasteful number, since it uses less digits than its factorization.

1221345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206 (or 200 counting only the distinct ones).

The product of its digits is 240, while the sum is 18.

The square root of 1221345 is about 1105.1447868945. The cubic root of 1221345 is about 106.8922256015.

Adding to 1221345 its reverse (5431221), we get a palindrome (6652566).

The spelling of 1221345 in words is "one million, two hundred twenty-one thousand, three hundred forty-five".