1305605563421 has 2 divisors, whose sum is σ = 1305605563422. Its totient is φ = 1305605563420.

The previous prime is 1305605563399. The next prime is 1305605563429. The reversal of 1305605563421 is 1243655065031.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 902526600196 + 403078963225 = 950014^2 + 634885^2 .

It is a cyclic number.

It is not a de Polignac number, because 1305605563421 - 2⁶ = 1305605563357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1305605563429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 652802781710 + 652802781711.

It is an arithmetic number, because the mean of its divisors is an integer number (652802781711).

Almost surely, 2^{1305605563421} is an apocalyptic number.

It is an amenable number.

1305605563421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1305605563421 is an equidigital number, since it uses as much as digits as its factorization.

1305605563421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324000, while the sum is 41.

The spelling of 1305605563421 in words is "one trillion, three hundred five billion, six hundred five million, five hundred sixty-three thousand, four hundred twenty-one".