20281231 has 8 divisors (see below), whose sum is σ = 20638800. Its totient is φ = 19926720.

The previous prime is 20281229. The next prime is 20281241. The reversal of 20281231 is 13218202.

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 20281231 - 2¹ = 20281229 is a prime.

It is a super-2 number, since 2×20281231² = 822656661750722, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 20281199 and 20281208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20281211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15480 + ... + 16738.

It is an arithmetic number, because the mean of its divisors is an integer number (2579850).

Almost surely, 2^20281231 is an apocalyptic number.

20281231 is a deficient number, since it is larger than the sum of its proper divisors (357569).

20281231 is a wasteful number, since it uses less digits than its factorization.

20281231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1529.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 20281231 is about 4503.4687741784. The cubic root of 20281231 is about 272.7081416244.

Adding to 20281231 its reverse (13218202), we get a palindrome (33499433).

The spelling of 20281231 in words is "twenty million, two hundred eighty-one thousand, two hundred thirty-one".