1305320197891 has 2 divisors, whose sum is σ = 1305320197892. Its totient is φ = 1305320197890.

The previous prime is 1305320197889. The next prime is 1305320197933. The reversal of 1305320197891 is 1987910235031.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1305320197891 - 2¹ = 1305320197889 is a prime.

Together with 1305320197889, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1305320197691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 652660098945 + 652660098946.

It is an arithmetic number, because the mean of its divisors is an integer number (652660098946).

Almost surely, 2^{1305320197891} is an apocalyptic number.

1305320197891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1305320197891 is an equidigital number, since it uses as much as digits as its factorization.

1305320197891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 408240, while the sum is 49.

The spelling of 1305320197891 in words is "one trillion, three hundred five billion, three hundred twenty million, one hundred ninety-seven thousand, eight hundred ninety-one".