281220001 has 8 divisors (see below), whose sum is σ = 298477224. Its totient is φ = 264042240.

The previous prime is 281219963. The next prime is 281220029. The reversal of 281220001 is 100022182.

It can be written as a sum of positive squares in 4 ways, for example, as 56250000 + 224970001 = 7500^2 + 14999^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 281220001 - 2¹¹ = 281217953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (281220031) 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 7 ways as a sum of consecutive naturals, for example, 12490 + ... + 26803.

It is an arithmetic number, because the mean of its divisors is an integer number (37309653).

Almost surely, 2^281220001 is an apocalyptic number.

It is an amenable number.

281220001 is a deficient number, since it is larger than the sum of its proper divisors (17257223).

281220001 is a wasteful number, since it uses less digits than its factorization.

281220001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39731.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 281220001 is about 16769.6154100206. The cubic root of 281220001 is about 655.1620530214.

Adding to 281220001 its reverse (100022182), we get a palindrome (381242183).

The spelling of 281220001 in words is "two hundred eighty-one million, two hundred twenty thousand, one".