491151808 has 56 divisors (see below), whose sum is σ = 1130556032. Its totient is φ = 207339264.

The previous prime is 491151797. The next prime is 491151863. The reversal of 491151808 is 808151194.

It is a tau number, because it is divible by the number of its divisors (56).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21835 + ... + 38197.

Almost surely, 2^491151808 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 491151808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (565278016).

491151808 is an abundant number, since it is smaller than the sum of its proper divisors (639404224).

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

491151808 is a wasteful number, since it uses less digits than its factorization.

491151808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16449 (or 16439 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 37.

The square root of 491151808 is about 22161.9450409931. The cubic root of 491151808 is about 788.9907573655.

The spelling of 491151808 in words is "four hundred ninety-one million, one hundred fifty-one thousand, eight hundred eight".