281861856 has 120 divisors (see below), whose sum is σ = 851641560. Its totient is φ = 91383552.

The previous prime is 281861771. The next prime is 281861873. The reversal of 281861856 is 658168182.

281861856 is a `hidden beast` number, since 28 + 1 + 8 + 618 + 5 + 6 = 666.

It is a super-2 number, since 2×281861856² = 158892211735529472, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 94435 + ... + 97373.

It is an arithmetic number, because the mean of its divisors is an integer number (7097013).

Almost surely, 2^281861856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 281861856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (425820780).

281861856 is an abundant number, since it is smaller than the sum of its proper divisors (569779704).

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

281861856 is a wasteful number, since it uses less digits than its factorization.

281861856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2998 (or 2981 counting only the distinct ones).

The product of its digits is 184320, while the sum is 45.

The square root of 281861856 is about 16788.7419421468. The cubic root of 281861856 is about 655.6601203862.

The spelling of 281861856 in words is "two hundred eighty-one million, eight hundred sixty-one thousand, eight hundred fifty-six".