491431920 has 160 divisors (see below), whose sum is σ = 1843596288. Its totient is φ = 105713664.

The previous prime is 491431909. The next prime is 491431943. The reversal of 491431920 is 29134194.

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, 19957 + ... + 37163.

Almost surely, 2^491431920 is an apocalyptic number.

491431920 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 491431920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (921798144).

491431920 is an abundant number, since it is smaller than the sum of its proper divisors (1352164368).

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

491431920 is a wasteful number, since it uses less digits than its factorization.

491431920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17247 (or 17241 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 491431920 is about 22168.2638021113. The cubic root of 491431920 is about 789.1407203534.

The spelling of 491431920 in words is "four hundred ninety-one million, four hundred thirty-one thousand, nine hundred twenty".