491796209 has 4 divisors (see below), whose sum is σ = 517680240. Its totient is φ = 465912180.

The previous prime is 491796191. The next prime is 491796257. The reversal of 491796209 is 902697194.

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.

It is a cyclic number.

It is not a de Polignac number, because 491796209 - 2¹² = 491792113 is a prime.

It is a super-2 number, since 2×491796209² = 483727022373543362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491796259) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12941987 + ... + 12942024.

It is an arithmetic number, because the mean of its divisors is an integer number (129420060).

Almost surely, 2^491796209 is an apocalyptic number.

It is an amenable number.

491796209 is a deficient number, since it is larger than the sum of its proper divisors (25884031).

491796209 is a wasteful number, since it uses less digits than its factorization.

491796209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25884030.

The product of its (nonzero) digits is 244944, while the sum is 47.

The square root of 491796209 is about 22176.4787331082. The cubic root of 491796209 is about 789.3356637885.

The spelling of 491796209 in words is "four hundred ninety-one million, seven hundred ninety-six thousand, two hundred nine".