1721383609 has 4 divisors (see below), whose sum is σ = 1877873040. Its totient is φ = 1564894180.

The previous prime is 1721383591. The next prime is 1721383649. The reversal of 1721383609 is 9063831271.

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, and also an emirpimes, since its reverse is a distinct semiprime: 9063831271 = 11 ⋅823984661.

It is a cyclic number.

It is not a de Polignac number, because 1721383609 - 2⁵ = 1721383577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1721383649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78244699 + ... + 78244720.

It is an arithmetic number, because the mean of its divisors is an integer number (469468260).

Almost surely, 2^1721383609 is an apocalyptic number.

It is an amenable number.

1721383609 is a deficient number, since it is larger than the sum of its proper divisors (156489431).

1721383609 is a wasteful number, since it uses less digits than its factorization.

1721383609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156489430.

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 1721383609 is about 41489.5602411016. The cubic root of 1721383609 is about 1198.4664690798.

The spelling of 1721383609 in words is "one billion, seven hundred twenty-one million, three hundred eighty-three thousand, six hundred nine".