491263440 has 80 divisors (see below), whose sum is σ = 1589148288. Its totient is φ = 125306368.

The previous prime is 491263351. The next prime is 491263453. The reversal of 491263440 is 44362194.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38979 + ... + 50018.

Almost surely, 2^491263440 is an apocalyptic number.

491263440 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

491263440 is an abundant number, since it is smaller than the sum of its proper divisors (1097884848).

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

491263440 is a wasteful number, since it uses less digits than its factorization.

491263440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89036 (or 89030 counting only the distinct ones).

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

The square root of 491263440 is about 22164.4634494048. The cubic root of 491263440 is about 789.0505283927.

The spelling of 491263440 in words is "four hundred ninety-one million, two hundred sixty-three thousand, four hundred forty".