491342640 has 80 divisors (see below), whose sum is σ = 1525423200. Its totient is φ = 130830336.

The previous prime is 491342597. The next prime is 491342659. The reversal of 491342640 is 46243194.

It is a tau number, because it is divible by the number of its divisors (80).

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

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 15 ways as a sum of consecutive naturals, for example, 241146 + ... + 243174.

It is an arithmetic number, because the mean of its divisors is an integer number (19067790).

Almost surely, 2^491342640 is an apocalyptic number.

491342640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

491342640 is an abundant number, since it is smaller than the sum of its proper divisors (1034080560).

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

491342640 is a wasteful number, since it uses less digits than its factorization.

491342640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3054 (or 3048 counting only the distinct ones).

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

The square root of 491342640 is about 22166.2500211470. The cubic root of 491342640 is about 789.0929288909.

The spelling of 491342640 in words is "four hundred ninety-one million, three hundred forty-two thousand, six hundred forty".