281840128 has 20 divisors (see below), whose sum is σ = 563130810. Its totient is φ = 140919808.

The previous prime is 281840113. The next prime is 281840131. The reversal of 281840128 is 821048182.

It can be written as a sum of positive squares in only one way, i.e., 254466304 + 27373824 = 15952^2 + 5232^2 .

It is a junction number, because it is equal to n+sod(n) for n = 281840093 and 281840102.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 274723 + ... + 275746.

Almost surely, 2^281840128 is an apocalyptic number.

It is an amenable number.

281840128 is a deficient number, since it is larger than the sum of its proper divisors (281290682).

281840128 is an frugal number, since it uses more digits than its factorization.

281840128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550487 (or 550471 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 34.

The square root of 281840128 is about 16788.0948293724. The cubic root of 281840128 is about 655.6432722401.

The spelling of 281840128 in words is "two hundred eighty-one million, eight hundred forty thousand, one hundred twenty-eight".