491636257 has 12 divisors (see below), whose sum is σ = 573078000. Its totient is φ = 420537096.

The previous prime is 491636231. The next prime is 491636261. The reversal of 491636257 is 752636194.

It is not a de Polignac number, because 491636257 - 2⁷ = 491636129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491636287) 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, 14398 + ... + 34504.

It is an arithmetic number, because the mean of its divisors is an integer number (47756500).

Almost surely, 2^491636257 is an apocalyptic number.

It is an amenable number.

491636257 is a deficient number, since it is larger than the sum of its proper divisors (81441743).

491636257 is a wasteful number, since it uses less digits than its factorization.

491636257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20620 (or 20613 counting only the distinct ones).

The product of its digits is 272160, while the sum is 43.

The square root of 491636257 is about 22172.8720963253. The cubic root of 491636257 is about 789.2500798914.

The spelling of 491636257 in words is "four hundred ninety-one million, six hundred thirty-six thousand, two hundred fifty-seven".