509379840 has 360 divisors, whose sum is σ = 1936546920. Its totient is φ = 127844352.

The previous prime is 509379839. The next prime is 509379847. The reversal of 509379840 is 48973905.

It can be written as a sum of positive squares in 4 ways, for example, as 67371264 + 442008576 = 8208^2 + 21024^2 .

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Saint-Exupery number, since it is equal to the product of the sides of a Pythagorean triangle: 1020 × 612 × 816.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (509379847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 29963512 + ... + 29963528.

It is an arithmetic number, because the mean of its divisors is an integer number (5379297).

Almost surely, 2^509379840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 509379840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (968273460).

509379840 is an abundant number, since it is smaller than the sum of its proper divisors (1427167080).

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

509379840 is an frugal number, since it uses more digits than its factorization.

509379840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 27 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The square root of 509379840 is about 22569.4448314530. Note that the first 3 decimals coincide. The cubic root of 509379840 is about 798.6329987984.

The spelling of 509379840 in words is "five hundred nine million, three hundred seventy-nine thousand, eight hundred forty".