491387520 has 128 divisors (see below), whose sum is σ = 1686867840. Its totient is φ = 120950784.

The previous prime is 491387509. The next prime is 491387551. The reversal of 491387520 is 25783194.

491387520 = T₂₆₇ + T₂₆₈ + ... + T₁₄₃₆.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (39).

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, 15117 + ... + 34803.

It is an arithmetic number, because the mean of its divisors is an integer number (13178655).

Almost surely, 2^491387520 is an apocalyptic number.

491387520 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 491387520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (843433920).

491387520 is an abundant number, since it is smaller than the sum of its proper divisors (1195480320).

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

491387520 is a wasteful number, since it uses less digits than its factorization.

491387520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19722 (or 19710 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 39.

The square root of 491387520 is about 22167.2623478859. The cubic root of 491387520 is about 789.1169538174.

The spelling of 491387520 in words is "four hundred ninety-one million, three hundred eighty-seven thousand, five hundred twenty".