285720428 has 96 divisors (see below), whose sum is σ = 636088320. Its totient is φ = 109866240.

The previous prime is 285720371. The next prime is 285720433. The reversal of 285720428 is 824027582.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 285720391 and 285720400.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4264451 + ... + 4264517.

It is an arithmetic number, because the mean of its divisors is an integer number (6625920).

Almost surely, 2^285720428 is an apocalyptic number.

285720428 is a gapful number since it is divisible by the number (28) 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 285720428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (318044160).

285720428 is an abundant number, since it is smaller than the sum of its proper divisors (350367892).

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

285720428 is a wasteful number, since it uses less digits than its factorization.

285720428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 71680, while the sum is 38.

The square root of 285720428 is about 16903.2667848555. The cubic root of 285720428 is about 658.6384757440.

The spelling of 285720428 in words is "two hundred eighty-five million, seven hundred twenty thousand, four hundred twenty-eight".