1720718749 has 2 divisors, whose sum is σ = 1720718750. Its totient is φ = 1720718748.

The previous prime is 1720718689. The next prime is 1720718771. The reversal of 1720718749 is 9478170271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1536248025 + 184470724 = 39195^2 + 13582^2 .

It is an emirp because it is prime and its reverse (9478170271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1720718749 - 2²⁹ = 1183847837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1720718699 and 1720718708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1720718789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860359374 + 860359375.

It is an arithmetic number, because the mean of its divisors is an integer number (860359375).

Almost surely, 2^1720718749 is an apocalyptic number.

It is an amenable number.

1720718749 is a deficient number, since it is larger than the sum of its proper divisors (1).

1720718749 is an equidigital number, since it uses as much as digits as its factorization.

1720718749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 197568, while the sum is 46.

The square root of 1720718749 is about 41481.5470902424. The cubic root of 1720718749 is about 1198.3121523197.

The spelling of 1720718749 in words is "one billion, seven hundred twenty million, seven hundred eighteen thousand, seven hundred forty-nine".