491211000 has 512 divisors, whose sum is σ = 2048716800. Its totient is φ = 106444800.

The previous prime is 491210989. The next prime is 491211011. The reversal of 491211000 is 112194.

It is an interprime number because it is at equal distance from previous prime (491210989) and next prime (491211011).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4346944 + ... + 4347056.

It is an arithmetic number, because the mean of its divisors is an integer number (4001400).

Almost surely, 2^491211000 is an apocalyptic number.

491211000 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 491211000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1024358400).

491211000 is an abundant number, since it is smaller than the sum of its proper divisors (1557505800).

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

491211000 is a wasteful number, since it uses less digits than its factorization.

491211000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173 (or 153 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 491211000 is about 22163.2804431113. The cubic root of 491211000 is about 789.0224516157.

Adding to 491211000 its reverse (112194), we get a palindrome (491323194).

The spelling of 491211000 in words is "four hundred ninety-one million, two hundred eleven thousand".