491187920 has 20 divisors (see below), whose sum is σ = 1142012100. Its totient is φ = 196475136.

The previous prime is 491187911. The next prime is 491187937. The reversal of 491187920 is 29781194.

It can be written as a sum of positive squares in 2 ways, for example, as 122855056 + 368332864 = 11084^2 + 19192^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3069845 + ... + 3070004.

It is an arithmetic number, because the mean of its divisors is an integer number (57100605).

Almost surely, 2^491187920 is an apocalyptic number.

491187920 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

491187920 is an abundant number, since it is smaller than the sum of its proper divisors (650824180).

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

491187920 is a wasteful number, since it uses less digits than its factorization.

491187920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6139862 (or 6139856 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 41.

The square root of 491187920 is about 22162.7597559510. The cubic root of 491187920 is about 789.0100937740.

The spelling of 491187920 in words is "four hundred ninety-one million, one hundred eighty-seven thousand, nine hundred twenty".