491657256 has 128 divisors (see below), whose sum is σ = 1414454400. Its totient is φ = 158146560.

The previous prime is 491657251. The next prime is 491657267. The reversal of 491657256 is 652756194.

It is not an unprimeable number, because it can be changed into a prime (491657251) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 766696 + ... + 767336.

It is an arithmetic number, because the mean of its divisors is an integer number (11050425).

Almost surely, 2^491657256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 491657256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (707227200).

491657256 is an abundant number, since it is smaller than the sum of its proper divisors (922797144).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

491657256 is a wasteful number, since it uses less digits than its factorization.

491657256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 776 (or 766 counting only the distinct ones).

The product of its digits is 453600, while the sum is 45.

The square root of 491657256 is about 22173.3456203614. The cubic root of 491657256 is about 789.2613166722.

The spelling of 491657256 in words is "four hundred ninety-one million, six hundred fifty-seven thousand, two hundred fifty-six".