287345920 has 72 divisors (see below), whose sum is σ = 712109160. Its totient is φ = 110960640.

The previous prime is 287345893. The next prime is 287345957. The reversal of 287345920 is 29543782.

It can be written as a sum of positive squares in 4 ways, for example, as 8856576 + 278489344 = 2976^2 + 16688^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33250 + ... + 40990.

It is an arithmetic number, because the mean of its divisors is an integer number (9890405).

Almost surely, 2^287345920 is an apocalyptic number.

287345920 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 287345920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (356054580).

287345920 is an abundant number, since it is smaller than the sum of its proper divisors (424763240).

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

287345920 is an equidigital number, since it uses as much as digits as its factorization.

287345920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7791 (or 7777 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 40.

The square root of 287345920 is about 16951.2807775696. The cubic root of 287345920 is about 659.8851345862.

The spelling of 287345920 in words is "two hundred eighty-seven million, three hundred forty-five thousand, nine hundred twenty".