1720780513 has 2 divisors, whose sum is σ = 1720780514. Its totient is φ = 1720780512.

The previous prime is 1720780507. The next prime is 1720780517. The reversal of 1720780513 is 3150870271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1460539089 + 260241424 = 38217^2 + 16132^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1720780513 is a prime.

It is a super-2 number, since 2×1720780513² = 5922171147841086338, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1720780517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860390256 + 860390257.

It is an arithmetic number, because the mean of its divisors is an integer number (860390257).

Almost surely, 2^1720780513 is an apocalyptic number.

It is an amenable number.

1720780513 is a deficient number, since it is larger than the sum of its proper divisors (1).

1720780513 is an equidigital number, since it uses as much as digits as its factorization.

1720780513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11760, while the sum is 34.

The square root of 1720780513 is about 41482.2915591702. The cubic root of 1720780513 is about 1198.3264896746.

The spelling of 1720780513 in words is "one billion, seven hundred twenty million, seven hundred eighty thousand, five hundred thirteen".