20608281 has 12 divisors (see below), whose sum is σ = 30494100. Its totient is φ = 13403520.

The previous prime is 20608277. The next prime is 20608349. The reversal of 20608281 is 18280602.

It can be written as a sum of positive squares in 2 ways, for example, as 8643600 + 11964681 = 2940^2 + 3459^2 .

It is not a de Polignac number, because 20608281 - 2² = 20608277 is a prime.

It is a super-2 number, since 2×20608281² = 849402491549922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20608271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27556 + ... + 28293.

It is an arithmetic number, because the mean of its divisors is an integer number (2541175).

Almost surely, 2^20608281 is an apocalyptic number.

It is an amenable number.

20608281 is a deficient number, since it is larger than the sum of its proper divisors (9885819).

20608281 is a wasteful number, since it uses less digits than its factorization.

20608281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55896 (or 55893 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 20608281 is about 4539.6344566496. The cubic root of 20608281 is about 274.1662061914.

Adding to 20608281 its reverse (18280602), we get a palindrome (38888883).

The spelling of 20608281 in words is "twenty million, six hundred eight thousand, two hundred eighty-one".