1304005021 has 12 divisors (see below), whose sum is σ = 1434507676. Its totient is φ = 1184483520.

The previous prime is 1304005013. The next prime is 1304005037. The reversal of 1304005021 is 1205004031.

It can be written as a sum of positive squares in 2 ways, for example, as 1189215225 + 114789796 = 34485^2 + 10714^2 .

It is not a de Polignac number, because 1304005021 - 2³ = 1304005013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1304004986 and 1304005004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1304005051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 172105 + ... + 179521.

Almost surely, 2^1304005021 is an apocalyptic number.

1304005021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1304005021 is a deficient number, since it is larger than the sum of its proper divisors (130502655).

1304005021 is a wasteful number, since it uses less digits than its factorization.

1304005021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8892 (or 8881 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 1304005021 is about 36111.0096923362. The cubic root of 1304005021 is about 1092.5125164780.

Adding to 1304005021 its reverse (1205004031), we get a palindrome (2509009052).

The spelling of 1304005021 in words is "one billion, three hundred four million, five thousand, twenty-one".