1221503 has 2 divisors, whose sum is σ = 1221504. Its totient is φ = 1221502.

The previous prime is 1221499. The next prime is 1221523. The reversal of 1221503 is 3051221.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221503 - 2² = 1221499 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610751 + 610752.

It is an arithmetic number, because the mean of its divisors is an integer number (610752).

2^1221503 is an apocalyptic number.

1221503 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221503 is an equidigital number, since it uses as much as digits as its factorization.

1221503 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 1221503 is about 1105.2162684289. The cubic root of 1221503 is about 106.8968347942.

Adding to 1221503 its reverse (3051221), we get a palindrome (4272724).

The spelling of 1221503 in words is "one million, two hundred twenty-one thousand, five hundred three".