1728330997 has 4 divisors (see below), whose sum is σ = 1728724096. Its totient is φ = 1727937900.

The previous prime is 1728330983. The next prime is 1728331001. The reversal of 1728330997 is 7990338271.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1728330997 - 2⁷ = 1728330869 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1728330997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1728330917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 189879 + ... + 198772.

It is an arithmetic number, because the mean of its divisors is an integer number (432181024).

Almost surely, 2^1728330997 is an apocalyptic number.

It is an amenable number.

1728330997 is a deficient number, since it is larger than the sum of its proper divisors (393099).

1728330997 is an equidigital number, since it uses as much as digits as its factorization.

1728330997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393098.

The product of its (nonzero) digits is 571536, while the sum is 49.

The square root of 1728330997 is about 41573.2004661657. The cubic root of 1728330997 is about 1200.0766147843.

The spelling of 1728330997 in words is "one billion, seven hundred twenty-eight million, three hundred thirty thousand, nine hundred ninety-seven".