1728537749 has 4 divisors (see below), whose sum is σ = 1819513440. Its totient is φ = 1637562060.

The previous prime is 1728537731. The next prime is 1728537793. The reversal of 1728537749 is 9477358271.

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 a de Polignac number, because none of the positive numbers 2^k-1728537749 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1728537749.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1728537719) 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, 45487817 + ... + 45487854.

It is an arithmetic number, because the mean of its divisors is an integer number (454878360).

Almost surely, 2^1728537749 is an apocalyptic number.

1728537749 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1728537749 is a deficient number, since it is larger than the sum of its proper divisors (90975691).

1728537749 is an equidigital number, since it uses as much as digits as its factorization.

1728537749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90975690.

The product of its digits is 2963520, while the sum is 53.

The square root of 1728537749 is about 41575.6869937227. The cubic root of 1728537749 is about 1200.1244660249.

The spelling of 1728537749 in words is "one billion, seven hundred twenty-eight million, five hundred thirty-seven thousand, seven hundred forty-nine".