255428640 has 120 divisors (see below), whose sum is σ = 901495980. Its totient is φ = 68110848.

The previous prime is 255428627. The next prime is 255428653. The reversal of 255428640 is 46824552.

It is a happy number.

255428640 is a `hidden beast` number, since 2 + 5 + 5 + 4 + 2 + 8 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (255428627) and next prime (255428653).

It can be written as a sum of positive squares in 2 ways, for example, as 254338704 + 1089936 = 15948^2 + 1044^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 255428595 and 255428604.

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 3106 + ... + 22814.

Almost surely, 2^255428640 is an apocalyptic number.

255428640 is a gapful number since it is divisible by the number (20) 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 255428640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (450747990).

255428640 is an abundant number, since it is smaller than the sum of its proper divisors (646067340).

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

255428640 is a wasteful number, since it uses less digits than its factorization.

255428640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19736 (or 19719 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 36.

The square root of 255428640 is about 15982.1350263349. The cubic root of 255428640 is about 634.4876848204.

The spelling of 255428640 in words is "two hundred fifty-five million, four hundred twenty-eight thousand, six hundred forty".