491656251 has 8 divisors (see below), whose sum is σ = 665326144. Its totient is φ = 322878600.

The previous prime is 491656247. The next prime is 491656261. The reversal of 491656251 is 152656194.

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

It is not a de Polignac number, because 491656251 - 2² = 491656247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491656261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1222825 + ... + 1223226.

It is an arithmetic number, because the mean of its divisors is an integer number (83165768).

Almost surely, 2^491656251 is an apocalyptic number.

491656251 is a deficient number, since it is larger than the sum of its proper divisors (173669893).

491656251 is a wasteful number, since it uses less digits than its factorization.

491656251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2446121.

The product of its digits is 64800, while the sum is 39.

The square root of 491656251 is about 22173.3229580052. The cubic root of 491656251 is about 789.2607788936.

The spelling of 491656251 in words is "four hundred ninety-one million, six hundred fifty-six thousand, two hundred fifty-one".