20023281 has 10 divisors (see below), whose sum is σ = 29911442. Its totient is φ = 13348800.

The previous prime is 20023279. The next prime is 20023291. The reversal of 20023281 is 18232002.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 17514225 + 2509056 = 4185^2 + 1584^2 .

It is not a de Polignac number, because 20023281 - 2¹ = 20023279 is a prime.

It is a super-2 number, since 2×20023281² = 801863564009922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20023291) 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 9 ways as a sum of consecutive naturals, for example, 123520 + ... + 123681.

Almost surely, 2^20023281 is an apocalyptic number.

It is an amenable number.

20023281 is a deficient number, since it is larger than the sum of its proper divisors (9888161).

20023281 is an equidigital number, since it uses as much as digits as its factorization.

20023281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247213 (or 247204 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 20023281 is about 4474.7380928944. The cubic root of 20023281 is about 271.5470447460.

Adding to 20023281 its reverse (18232002), we get a palindrome (38255283).

The spelling of 20023281 in words is "twenty million, twenty-three thousand, two hundred eighty-one".