1305513221 has 6 divisors (see below), whose sum is σ = 1310961510. Its totient is φ = 1300069608.

The previous prime is 1305513211. The next prime is 1305513227. The reversal of 1305513221 is 1223155031.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 820192321 + 485320900 = 28639^2 + 22030^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1305513221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1305513227) 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 in 5 ways as a sum of consecutive naturals, for example, 591506 + ... + 593708.

It is an arithmetic number, because the mean of its divisors is an integer number (218493585).

Almost surely, 2^1305513221 is an apocalyptic number.

It is an amenable number.

1305513221 is a deficient number, since it is larger than the sum of its proper divisors (5448289).

1305513221 is an frugal number, since it uses more digits than its factorization.

1305513221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4675 (or 2472 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 1305513221 is about 36131.8864854854. The cubic root of 1305513221 is about 1092.9335507813.

Adding to 1305513221 its reverse (1223155031), we get a palindrome (2528668252).

The spelling of 1305513221 in words is "one billion, three hundred five million, five hundred thirteen thousand, two hundred twenty-one".