281720 has 16 divisors (see below), whose sum is σ = 633960. Its totient is φ = 112672.

The previous prime is 281719. The next prime is 281737. The reversal of 281720 is 27182.

281720 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×281720³ = 67077102433344000, which contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 281692 and 281701.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3482 + ... + 3561.

2²⁸¹⁷²⁰ is an apocalyptic number.

281720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

281720 is an abundant number, since it is smaller than the sum of its proper divisors (352240).

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

281720 is a wasteful number, since it uses less digits than its factorization.

281720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7054 (or 7050 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 281720 is about 530.7730211682. The cubic root of 281720 is about 65.5550107948. Note that the first 3 decimals are identical.

It can be divided in two parts, 281 and 720, that added together give a palindrome (1001).

The spelling of 281720 in words is "two hundred eighty-one thousand, seven hundred twenty".