518688040 has 72 divisors (see below), whose sum is σ = 1268305290. Its totient is φ = 190824192.

The previous prime is 518688031. The next prime is 518688041. The reversal of 518688040 is 40886815.

It can be written as a sum of positive squares in 9 ways, for example, as 88623396 + 430064644 = 9414^2 + 20738^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 518687984 and 518688002.

It is not an unprimeable number, because it can be changed into a prime (518688041) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1872382 + ... + 1872658.

Almost surely, 2^518688040 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 518688040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (634152645).

518688040 is an abundant number, since it is smaller than the sum of its proper divisors (749617250).

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

518688040 is a wasteful number, since it uses less digits than its factorization.

518688040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 591 (or 297 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 40.

The square root of 518688040 is about 22774.7237085327. The cubic root of 518688040 is about 803.4682960901.

Multiplying 518688040 by its sum of digits (40), we get a square (20747521600 = 144040²).

518688040 divided by its sum of digits (40) gives a square (12967201 = 3601²).

The spelling of 518688040 in words is "five hundred eighteen million, six hundred eighty-eight thousand, forty".