1205221649 has 2 divisors, whose sum is σ = 1205221650. Its totient is φ = 1205221648.

The previous prime is 1205221639. The next prime is 1205221657. The reversal of 1205221649 is 9461225021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1126810624 + 78411025 = 33568^2 + 8855^2 .

It is a cyclic number.

It is not a de Polignac number, because 1205221649 - 2¹² = 1205217553 is a prime.

It is not a weakly prime, because it can be changed into another prime (1205221639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 602610824 + 602610825.

It is an arithmetic number, because the mean of its divisors is an integer number (602610825).

Almost surely, 2^1205221649 is an apocalyptic number.

It is an amenable number.

1205221649 is a deficient number, since it is larger than the sum of its proper divisors (1).

1205221649 is an equidigital number, since it uses as much as digits as its factorization.

1205221649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 1205221649 is about 34716.3023520651. The cubic root of 1205221649 is about 1064.1976806020.

The spelling of 1205221649 in words is "one billion, two hundred five million, two hundred twenty-one thousand, six hundred forty-nine".