491490009 has 12 divisors (see below), whose sum is σ = 751690836. Its totient is φ = 308385792.

The previous prime is 491489953. The next prime is 491490017. The reversal of 491490009 is 900094194.

It can be written as a sum of positive squares in 2 ways, for example, as 458174025 + 33315984 = 21405^2 + 5772^2 .

It is not a de Polignac number, because 491490009 - 2⁹ = 491489497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (491490029) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1606024 + ... + 1606329.

It is an arithmetic number, because the mean of its divisors is an integer number (62640903).

Almost surely, 2^491490009 is an apocalyptic number.

It is an amenable number.

491490009 is a deficient number, since it is larger than the sum of its proper divisors (260200827).

491490009 is a wasteful number, since it uses less digits than its factorization.

491490009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3212376 (or 3212373 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 491490009 is about 22169.5739471917. The cubic root of 491490009 is about 789.1718122079.

The spelling of 491490009 in words is "four hundred ninety-one million, four hundred ninety thousand, nine".