491233731840 has 288 divisors, whose sum is σ = 1750460342400. Its totient is φ = 130449899520.

The previous prime is 491233731811. The next prime is 491233731931. The reversal of 491233731840 is 48137332194.

491233731840 is a `hidden beast` number, since 491 + 23 + 37 + 31 + 84 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8299471 + ... + 8358449.

It is an arithmetic number, because the mean of its divisors is an integer number (6077987300).

Almost surely, 2^491233731840 is an apocalyptic number.

491233731840 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 491233731840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (875230171200).

491233731840 is an abundant number, since it is smaller than the sum of its proper divisors (1259226610560).

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

491233731840 is a wasteful number, since it uses less digits than its factorization.

491233731840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59250 (or 59230 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The spelling of 491233731840 in words is "four hundred ninety-one billion, two hundred thirty-three million, seven hundred thirty-one thousand, eight hundred forty".