287438640 has 80 divisors (see below), whose sum is σ = 894157056. Its totient is φ = 76384000.

The previous prime is 287438639. The next prime is 287438647. The reversal of 287438640 is 46834782.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 287438592 and 287438601.

It is not an unprimeable number, because it can be changed into a prime (287438647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72715 + ... + 76565.

Almost surely, 2^287438640 is an apocalyptic number.

287438640 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 287438640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (447078528).

287438640 is an abundant number, since it is smaller than the sum of its proper divisors (606718416).

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

287438640 is a wasteful number, since it uses less digits than its factorization.

287438640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4178 (or 4172 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 42.

The square root of 287438640 is about 16954.0154535732. The cubic root of 287438640 is about 659.9561036003.

It can be divided in two parts, 2874 and 38640, that added together give a palindrome (41514).

The spelling of 287438640 in words is "two hundred eighty-seven million, four hundred thirty-eight thousand, six hundred forty".