1728723169 has 2 divisors, whose sum is σ = 1728723170. Its totient is φ = 1728723168.

The previous prime is 1728723133. The next prime is 1728723173. The reversal of 1728723169 is 9613278271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 963481600 + 765241569 = 31040^2 + 27663^2 .

It is an emirp because it is prime and its reverse (9613278271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1728723169 - 2¹⁷ = 1728592097 is a prime.

It is a super-2 number, since 2×1728723169² = 5976967590074805122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1728723179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 864361584 + 864361585.

It is an arithmetic number, because the mean of its divisors is an integer number (864361585).

Almost surely, 2^1728723169 is an apocalyptic number.

It is an amenable number.

1728723169 is a deficient number, since it is larger than the sum of its proper divisors (1).

1728723169 is an equidigital number, since it uses as much as digits as its factorization.

1728723169 is an evil number, because the sum of its binary digits is even.

The product of its digits is 254016, while the sum is 46.

The square root of 1728723169 is about 41577.9168429588. The cubic root of 1728723169 is about 1200.1673768845.

The spelling of 1728723169 in words is "one billion, seven hundred twenty-eight million, seven hundred twenty-three thousand, one hundred sixty-nine".