281130021 has 10 divisors (see below), whose sum is σ = 419959782. Its totient is φ = 187419960.

The previous prime is 281130019. The next prime is 281130053. The reversal of 281130021 is 120031182.

It can be written as a sum of positive squares in only one way, i.e., 155376225 + 125753796 = 12465^2 + 11214^2 .

It is not a de Polignac number, because 281130021 - 2¹ = 281130019 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 281129976 and 281130003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (281131021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1735290 + ... + 1735451.

Almost surely, 2^281130021 is an apocalyptic number.

It is an amenable number.

281130021 is a deficient number, since it is larger than the sum of its proper divisors (138829761).

281130021 is an equidigital number, since it uses as much as digits as its factorization.

281130021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3470753 (or 3470744 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 281130021 is about 16766.9323670134. The cubic root of 281130021 is about 655.0921696918.

The spelling of 281130021 in words is "two hundred eighty-one million, one hundred thirty thousand, twenty-one".