1304645921 has 2 divisors, whose sum is σ = 1304645922. Its totient is φ = 1304645920.

The previous prime is 1304645897. The next prime is 1304645941. The reversal of 1304645921 is 1295464031.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1299963025 + 4682896 = 36055^2 + 2164^2 .

It is an emirp because it is prime and its reverse (1295464031) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1304645921 - 2³⁰ = 230904097 is a prime.

It is not a weakly prime, because it can be changed into another prime (1304645941) 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, 652322960 + 652322961.

It is an arithmetic number, because the mean of its divisors is an integer number (652322961).

Almost surely, 2^1304645921 is an apocalyptic number.

It is an amenable number.

1304645921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1304645921 is an equidigital number, since it uses as much as digits as its factorization.

1304645921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 1304645921 is about 36119.8826271626. The cubic root of 1304645921 is about 1092.6914719729.

The spelling of 1304645921 in words is "one billion, three hundred four million, six hundred forty-five thousand, nine hundred twenty-one".