1728643213 has 4 divisors (see below), whose sum is σ = 1885792608. Its totient is φ = 1571493820.

The previous prime is 1728643211. The next prime is 1728643229. The reversal of 1728643213 is 3123468271.

It is a happy number.

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 1728643213 - 2¹ = 1728643211 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1728643211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78574681 + ... + 78574702.

It is an arithmetic number, because the mean of its divisors is an integer number (471448152).

Almost surely, 2^1728643213 is an apocalyptic number.

It is an amenable number.

1728643213 is a deficient number, since it is larger than the sum of its proper divisors (157149395).

1728643213 is a wasteful number, since it uses less digits than its factorization.

1728643213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157149394.

The product of its digits is 48384, while the sum is 37.

The square root of 1728643213 is about 41576.9553118070. The cubic root of 1728643213 is about 1200.1488734280.

The spelling of 1728643213 in words is "one billion, seven hundred twenty-eight million, six hundred forty-three thousand, two hundred thirteen".