255640240 has 40 divisors (see below), whose sum is σ = 595140480. Its totient is φ = 102122496.

The previous prime is 255640223. The next prime is 255640241. The reversal of 255640240 is 42046552.

255640240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 255640199 and 255640208.

It is not an unprimeable number, because it can be changed into a prime (255640241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79137 + ... + 82303.

It is an arithmetic number, because the mean of its divisors is an integer number (14878512).

Almost surely, 2^255640240 is an apocalyptic number.

255640240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

255640240 is an abundant number, since it is smaller than the sum of its proper divisors (339500240).

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

255640240 is a wasteful number, since it uses less digits than its factorization.

255640240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4189 (or 4183 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 28.

The square root of 255640240 is about 15988.7535474158. The cubic root of 255640240 is about 634.6628420746.

Adding to 255640240 its reverse (42046552), we get a palindrome (297686792).

The spelling of 255640240 in words is "two hundred fifty-five million, six hundred forty thousand, two hundred forty".