281540 has 24 divisors (see below), whose sum is σ = 676032. Its totient is φ = 96480.

The previous prime is 281539. The next prime is 281549. The reversal of 281540 is 45182.

It is a Smith number, since the sum of its digits (20) coincides with the sum of the digits of its prime factors.

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

It is not an unprimeable number, because it can be changed into a prime (281549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 866 + ... + 1145.

It is an arithmetic number, because the mean of its divisors is an integer number (28168).

2²⁸¹⁵⁴⁰ is an apocalyptic number.

281540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

281540 is an abundant number, since it is smaller than the sum of its proper divisors (394492).

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

281540 is a wasteful number, since it uses less digits than its factorization.

281540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2027 (or 2025 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 281540 is about 530.6034300681. The cubic root of 281540 is about 65.5410460829.

The spelling of 281540 in words is "two hundred eighty-one thousand, five hundred forty".