1643245120997 has 2 divisors, whose sum is σ = 1643245120998. Its totient is φ = 1643245120996.

The previous prime is 1643245120991. The next prime is 1643245121071. The reversal of 1643245120997 is 7990215423461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1642585709956 + 659411041 = 1281634^2 + 25679^2 .

It is an emirp because it is prime and its reverse (7990215423461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1643245120997 - 2²⁴ = 1643228343781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1643245120991) 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, 821622560498 + 821622560499.

It is an arithmetic number, because the mean of its divisors is an integer number (821622560499).

Almost surely, 2^{1643245120997} is an apocalyptic number.

It is an amenable number.

1643245120997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1643245120997 is an equidigital number, since it uses as much as digits as its factorization.

1643245120997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3265920, while the sum is 53.

The spelling of 1643245120997 in words is "one trillion, six hundred forty-three billion, two hundred forty-five million, one hundred twenty thousand, nine hundred ninety-seven".