1305171438421 has 2 divisors, whose sum is σ = 1305171438422. Its totient is φ = 1305171438420.

The previous prime is 1305171438413. The next prime is 1305171438427. The reversal of 1305171438421 is 1248341715031.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 879682671396 + 425488767025 = 937914^2 + 652295^2 .

It is a cyclic number.

It is not a de Polignac number, because 1305171438421 - 2³ = 1305171438413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1305171438427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 652585719210 + 652585719211.

It is an arithmetic number, because the mean of its divisors is an integer number (652585719211).

Almost surely, 2^{1305171438421} is an apocalyptic number.

It is an amenable number.

1305171438421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1305171438421 is an equidigital number, since it uses as much as digits as its factorization.

1305171438421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80640, while the sum is 40.

The spelling of 1305171438421 in words is "one trillion, three hundred five billion, one hundred seventy-one million, four hundred thirty-eight thousand, four hundred twenty-one".