491432640 has 56 divisors (see below), whose sum is σ = 1560301680. Its totient is φ = 131048448.

The previous prime is 491432633. The next prime is 491432659. The reversal of 491432640 is 46234194.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 254995 + ... + 256914.

It is an arithmetic number, because the mean of its divisors is an integer number (27862530).

Almost surely, 2^491432640 is an apocalyptic number.

491432640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

491432640 is an abundant number, since it is smaller than the sum of its proper divisors (1068869040).

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

491432640 is a wasteful number, since it uses less digits than its factorization.

491432640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 511929 (or 511919 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 491432640 is about 22168.2800415368. The cubic root of 491432640 is about 789.1411057449.

The spelling of 491432640 in words is "four hundred ninety-one million, four hundred thirty-two thousand, six hundred forty".