491673509 has 8 divisors (see below), whose sum is σ = 503019072. Its totient is φ = 480450880.

The previous prime is 491673451. The next prime is 491673577. The reversal of 491673509 is 905376194.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 491673509 - 2¹⁶ = 491607973 is a prime.

It is a super-3 number, since 3×491673509³ (a number of 27 digits) contains 333 as substring.

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 491673509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491673709) 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 7 ways as a sum of consecutive naturals, for example, 22619 + ... + 38664.

It is an arithmetic number, because the mean of its divisors is an integer number (62877384).

Almost surely, 2^491673509 is an apocalyptic number.

It is an amenable number.

491673509 is a deficient number, since it is larger than the sum of its proper divisors (11345563).

491673509 is a wasteful number, since it uses less digits than its factorization.

491673509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61467.

The product of its (nonzero) digits is 204120, while the sum is 44.

The square root of 491673509 is about 22173.7121159268. The cubic root of 491673509 is about 789.2700135999.

The spelling of 491673509 in words is "four hundred ninety-one million, six hundred seventy-three thousand, five hundred nine".