491909806 has 8 divisors (see below), whose sum is σ = 744634440. Its totient is φ = 243698328.

The previous prime is 491909777. The next prime is 491909813. The reversal of 491909806 is 608909194.

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

It is a congruent number.

It is an unprimeable number.

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, 1128016 + ... + 1128451.

It is an arithmetic number, because the mean of its divisors is an integer number (93079305).

Almost surely, 2^491909806 is an apocalyptic number.

491909806 is a deficient number, since it is larger than the sum of its proper divisors (252724634).

491909806 is a wasteful number, since it uses less digits than its factorization.

491909806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2256578.

The product of its (nonzero) digits is 139968, while the sum is 46.

The square root of 491909806 is about 22179.0397898556. The cubic root of 491909806 is about 789.3964337164.

It can be divided in two parts, 49190 and 9806, that added together give a triangular number (58996 = T₃₄₃).

The spelling of 491909806 in words is "four hundred ninety-one million, nine hundred nine thousand, eight hundred six".