491487909 has 16 divisors (see below), whose sum is σ = 734214720. Its totient is φ = 289820160.

The previous prime is 491487823. The next prime is 491487949. The reversal of 491487909 is 909784194.

It is not a de Polignac number, because 491487909 - 2⁷ = 491487781 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491487949) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 200044 + ... + 202485.

It is an arithmetic number, because the mean of its divisors is an integer number (45888420).

Almost surely, 2^491487909 is an apocalyptic number.

It is an amenable number.

491487909 is a deficient number, since it is larger than the sum of its proper divisors (242726811).

491487909 is a wasteful number, since it uses less digits than its factorization.

491487909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402580.

The product of its (nonzero) digits is 653184, while the sum is 51.

The square root of 491487909 is about 22169.5265849318. The cubic root of 491487909 is about 789.1706882358.

The spelling of 491487909 in words is "four hundred ninety-one million, four hundred eighty-seven thousand, nine hundred nine".