1720661260117 has 2 divisors, whose sum is σ = 1720661260118. Its totient is φ = 1720661260116.

The previous prime is 1720661260103. The next prime is 1720661260141. The reversal of 1720661260117 is 7110621660271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1471868798436 + 248792461681 = 1213206^2 + 498791^2 .

It is an emirp because it is prime and its reverse (7110621660271) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1720661260117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1720661260117.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1720661260817) 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, 860330630058 + 860330630059.

It is an arithmetic number, because the mean of its divisors is an integer number (860330630059).

Almost surely, 2^{1720661260117} is an apocalyptic number.

It is an amenable number.

1720661260117 is a deficient number, since it is larger than the sum of its proper divisors (1).

1720661260117 is an equidigital number, since it uses as much as digits as its factorization.

1720661260117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 42336, while the sum is 40.

The spelling of 1720661260117 in words is "one trillion, seven hundred twenty billion, six hundred sixty-one million, two hundred sixty thousand, one hundred seventeen".