1720385279993 has 2 divisors, whose sum is σ = 1720385279994. Its totient is φ = 1720385279992.

The previous prime is 1720385279981. The next prime is 1720385280071. The reversal of 1720385279993 is 3999725830271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1504245831529 + 216139448464 = 1226477^2 + 464908^2 .

It is an emirp because it is prime and its reverse (3999725830271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1720385279993 - 2²⁰ = 1720384231417 is a prime.

It is not a weakly prime, because it can be changed into another prime (1720385279933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860192639996 + 860192639997.

It is an arithmetic number, because the mean of its divisors is an integer number (860192639997).

Almost surely, 2^{1720385279993} is an apocalyptic number.

It is an amenable number.

1720385279993 is a deficient number, since it is larger than the sum of its proper divisors (1).

1720385279993 is an equidigital number, since it uses as much as digits as its factorization.

1720385279993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51438240, while the sum is 65.

The spelling of 1720385279993 in words is "one trillion, seven hundred twenty billion, three hundred eighty-five million, two hundred seventy-nine thousand, nine hundred ninety-three".