1245305221 has 4 divisors (see below), whose sum is σ = 1245735052. Its totient is φ = 1244875392.

The previous prime is 1245305183. The next prime is 1245305297. The reversal of 1245305221 is 1225035421.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 871076196 + 374229025 = 29514^2 + 19345^2 .

It is a cyclic number.

It is not a de Polignac number, because 1245305221 - 2⁷ = 1245305093 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 (1245305821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210540 + ... + 216373.

It is an arithmetic number, because the mean of its divisors is an integer number (311433763).

Almost surely, 2^1245305221 is an apocalyptic number.

It is an amenable number.

1245305221 is a deficient number, since it is larger than the sum of its proper divisors (429831).

1245305221 is an equidigital number, since it uses as much as digits as its factorization.

1245305221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 429830.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 1245305221 is about 35288.8823994187. The cubic root of 1245305221 is about 1075.8670404687.

The spelling of 1245305221 in words is "one billion, two hundred forty-five million, three hundred five thousand, two hundred twenty-one".