491309000 has 128 divisors (see below), whose sum is σ = 1415232000. Its totient is φ = 155462400.

The previous prime is 491308999. The next prime is 491309009. The reversal of 491309000 is 903194.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is not an unprimeable number, because it can be changed into a prime (491309009) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 88301 + ... + 93699.

It is an arithmetic number, because the mean of its divisors is an integer number (11056500).

Almost surely, 2^491309000 is an apocalyptic number.

491309000 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 491309000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (707616000).

491309000 is an abundant number, since it is smaller than the sum of its proper divisors (923923000).

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

491309000 is a wasteful number, since it uses less digits than its factorization.

491309000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5440 (or 5426 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 491309000 is about 22165.4911969034. The cubic root of 491309000 is about 789.0749199431.

The spelling of 491309000 in words is "four hundred ninety-one million, three hundred nine thousand".