1305011021 has 2 divisors, whose sum is σ = 1305011022. Its totient is φ = 1305011020.

The previous prime is 1305011011. The next prime is 1305011039. The reversal of 1305011021 is 1201105031.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1073545225 + 231465796 = 32765^2 + 15214^2 .

It is a cyclic number.

It is not a de Polignac number, because 1305011021 - 2¹⁴ = 1304994637 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1305010987 and 1305011005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1305011011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 652505510 + 652505511.

It is an arithmetic number, because the mean of its divisors is an integer number (652505511).

Almost surely, 2^1305011021 is an apocalyptic number.

It is an amenable number.

1305011021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1305011021 is an equidigital number, since it uses as much as digits as its factorization.

1305011021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30, while the sum is 14.

The square root of 1305011021 is about 36124.9362767604. The cubic root of 1305011021 is about 1092.7933909283.

Adding to 1305011021 its reverse (1201105031), we get a palindrome (2506116052).

The spelling of 1305011021 in words is "one billion, three hundred five million, eleven thousand, twenty-one".