100809281 has 2 divisors, whose sum is σ = 100809282. Its totient is φ = 100809280.

The previous prime is 100809263. The next prime is 100809311. The reversal of 100809281 is 182908001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79566400 + 21242881 = 8920^2 + 4609^2 .

It is a cyclic number.

It is not a de Polignac number, because 100809281 - 2¹⁴ = 100792897 is a prime.

It is a super-2 number, since 2×100809281² = 20325022271473922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (100809251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50404640 + 50404641.

It is an arithmetic number, because the mean of its divisors is an integer number (50404641).

Almost surely, 2^100809281 is an apocalyptic number.

It is an amenable number.

100809281 is a deficient number, since it is larger than the sum of its proper divisors (1).

100809281 is an equidigital number, since it uses as much as digits as its factorization.

100809281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 29.

The square root of 100809281 is about 10040.3825126337. The cubic root of 100809281 is about 465.4076373032.

The spelling of 100809281 in words is "one hundred million, eight hundred nine thousand, two hundred eighty-one".