285721344 has 126 divisors (see below), whose sum is σ = 855657236. Its totient is φ = 95178240.

The previous prime is 285721339. The next prime is 285721379. The reversal of 285721344 is 443127582.

It is a happy number.

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

Its product of digits (53760) is a multiple of the sum of its prime divisors (1536).

It is a junction number, because it is equal to n+sod(n) for n = 285721299 and 285721308.

It is an unprimeable number.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 185859 + ... + 187389.

Almost surely, 2^285721344 is an apocalyptic number.

285721344 is a gapful number since it is divisible by the number (24) 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 285721344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (427828618).

285721344 is an abundant number, since it is smaller than the sum of its proper divisors (569935892).

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

285721344 is an frugal number, since it uses more digits than its factorization.

285721344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1565 (or 1536 counting only the distinct ones).

The product of its digits is 53760, while the sum is 36.

The square root of 285721344 is about 16903.2938801880. The cubic root of 285721344 is about 658.6391795931.

The spelling of 285721344 in words is "two hundred eighty-five million, seven hundred twenty-one thousand, three hundred forty-four".